animal beh final
Zahavi's Handicap Principle
Females prefer handicaps!! Zahavi (1977) proposed that receivers should only attend to costly signals, which can only be produced by honest senders. Exaggerated traits are handicaps (example= the long tail of male widow bird) Handicap principle= signals should impose handicaps (costs) on sender to ensure honesty
Prolactin and Maternal Care in Rats (Bridges et al. 1990) Results
Females treated with prolactin displayed significantly higher levels of parental care behaviour than controls
Juvenile Hormones and Parental Care in Earwigs (Rankin et al. 1995) Results
Females with enhanced juvenile hormones exhibited reduced parental care
true
Fewer eggs means more surviving young
Strategy - produce more sperm when there is high competition
Small testes in monogamous mating systems. Large testis size in Polyandrous mating systems.
In what cases is male-only care favoured?
Female costs are higher than male costs: - Indeterminate growth - External fertilization - Iteroparity
runaway sexual selection
Female preference becomes genetically linked to the male trait. as the frequency of one changes, the frequency of the other changes as well.
Can you describe how sexual reproduction occurs in redback spider
Female redback spiders are much bigger than males. During mating, the male spider allows the female to eat him by doing a somersault so that his body is positioned over the female's mouth in order to increase fertility because he is able to spend more time with the female. The male spider spends his whole life looking for a female so when he finally finds one, he wants to ensure successful reproduction so he lets the female redback spider cannibalize him.
What aspects of jumping spider courtship indicate a history of antagonistic coevolution?
Females evolve resistance to male exploitation. Benefits females to evolve resistance
Why are biological clocks are entrained on environmental cues?
So that they are appropriate to the current environment. Set by information from the optic lobe
Why do some researchers see a link between language and consciousne
Some accounts have shown that people who lack language are unable to 'think' the same way as other people do until they develop language of their own. Ie. Helen K
Females clumped on a patchy resource...?
Some males can defend more than one female Mating system: polygyny females moved to areas where there is sufficient food, and males followed
Why are optimal foraging models often constructed after field data has been collected?
Sometimes environmental specificities impact the model. Sometimes model depends on what others are doing.
What is the purpose of sex-limited gene expression (i.e. X and Y genotypes)?
it is a way to limit the damage caused by sexually antagonistic genes
Receiver pre-adaptations to signal evolution according to the receiver-bias models:
it is the receiving apparatus that has undergone prior selection for functions other than social communication, such as prey or predator detection, and therefore more sensitive to certain types of stimuli social signals then evolve to exploit these well-developed receiver sensitivities
genetic mosaic
its body is built of a mixture of cells of two or more different genotypes; in mammals, arise by several different mechanisms including fusion of two different zygotes/early embryos or from lyonization
how is the overall arrangement of a bird's brain similar to that of a human
its similar bc they have a cerebrum, cerebellum and brain stem. the cerebrum is divided into 2 hemispheres, as is the brain stem. it controls the birds automatic functions
Other displays primate example
juvenile behaviors such as begins and grooming solicitation are used by adult senders to trigger nonaggressive, parental response by the receiver. Primates use sexual behaviors to deflect aggression i.e., subordinate primates (males and females) use a form of female-mounting solicitation (presenting the rear end) against aggressive dominants.
incubation
keeping the egg warm
ornaments
traits used in visual displays- bright colors or other elaborate structures. show other males they are superior, if evenly matched a fight will most likely happen
testosterone can have both activational and organizational effect
true
type II males midshipmen fish, sneakers, never develop into type I males nest defenders
true
not all signals undergo the same degree of ritualization. true or false. provide a little more info on this. why
true -if the incipient signal from the outset is well associated with the context and provides all of the information the receiver needs, it may not be ritualized at all. -a minimally ritualized signal may be difficult to distinguish from a cue.
summary of who benefits from different forms of communication
true communication: receiver and sender benefit manipulation deceit: receiver-possible detriment, sender-benefits Eavesdropping exploitation: receiver-benefits, sender-possible detriment ignore spite: receiver-possible detriment, Sender-possible detriment
who benefits in communication??
true communication= both sender and receiver benefit from communication (information exchange)
Honest Signaling: Predator-Prey Communication
two examples where information of fitness is communicated to potential predator: stotting gazelle jumps when its running away from hunting dogs because high jumps are an indicator of good fitness and that the dogs should find an easier prey. skylark and merlin. -the skylark continuously sings even when flying away from a predator because it indicates that they should chase someone else (because skylark is so fit that he can sing while running away) **in both cases, signal production is condition dependent.
defensive
type of mutualism - partnerships providing protection against herbivores, predators, or parasites etc: cleaner fish
How do Y carrying species overcome degeneration of the y chromosome?
undergo cycles of rebirth and degeneration
dioecious species
are species where the individuals are either male or female for their entire lifetime
when is sperm competition the strongest?
as female promiscuity increases competition among different males increases
Model for Kin Selection
c=cost b=benefit r=relatedness c/b <r
3. Ignore (spite)
cases when no one benefits; stimuli will be ignored
Associated effect
change in behavior directly linked with hormonal activity
Adaptation
characteristic that confers a higher fitness
What are the four types of sex ratios?
1) primary 2) secondary 3) tertiary 4) operational
crop
a special sac in the esophagus
sneakers
do not hold territory, hide near mate and use a strategy to cuckhold
extra pair copulations
genetic choices
Monogamy
having only one mate, one male + one female
choosy about mates
less choosy, more choosy
R. A. Fisher
proposed runaway sexual selection
Nikko Tinbergen
responsible for developing the four questions or levels of analysis
genes
the replicator or unit of selection
reproductive skew theory
variable reproductive opportunities among potential breeders
What are the four potential reasons for evolution of self-sacrificing behavior?
1) Cooperation and Mutualism (Good of the Species) 2) Manipulated Altruism (Manipulation) 3) Reciprocal Altruism 4) Kin Selection *Cooperation and Mutualism are (+), (+) so they are not altruism*
3 nuclei involved in song production:
1) Higher Vocal Center (HVC) 2) Robust Archistraitum (RA) 3) Parts of hypoglossal nuclei (nXIIts)- neurons leading to the avian larynx
What are the two types of polygamous and what do they mean?
1) Polygynous: one male, many females 2) Polyandrous: one female, many males
How many genes have the X and Y chromosome lost in reality and according to the "impending demise of males" hypothesis?
1) X chromosomes have not lost any genes 2) Y chromosomes lost a substantial number of genes up until 6 mya, and have since not changed 3) according to the impending demise hypothesis, the Y chromosome should continue to lose genes until it no longer exists
Parental Care Tradeoff in Treehoppers (Zink 2003) Predictions (2)
1. Egg guarding will increase egg survival and enhance current reproduction 2. Increased parental care (guarding) will decrease future reproductive success
Son relatedness to mother is
100%
epigamic=
= attracting opposite sex at breeding time.
Intentional movements=
= the preparatory and incomplete initial components of normal behaviors like foraging, fleeing, attacking, or grooming. these movements provide information about what the sender is likely to do next..... may become ritualized into signals of intent
definition of signal
=a packet of energy or matter generated by one individual (the sender) evolved as the result of natural selection for its effects in altering the behavior of a second individual (the receiver)
displacement behavior=
=acts that are apparently irrelevant to the motivational system in which they appear and are interspersed between relevant acts (tinbergen 1952) acts that are apparently irrelevant to the two motivational systems; these perhaps serve to release frustration or tension
motivational conflict: Redirected Behaviors redirected behaviors= give examples
=acts that are appropriate to the context but is directed toward an irrelevant target. examples: -attacking an innocent bystander or an inanimate object during a fight -drinking or feeding movements directed at smooth surfaces or shiny pebbles by a thirsty or hungry animal denied access to water or food -male copulating with an inanimate object after being rejected by female.
fluffing of feathers or fur (piloerection)=
=common thermoregulatory response in birds and mammals is frequently ritualized for visual signals; usually restricted to a small part of body to exaggerate display
Why produce sexually?
Animals reproduce sexually to have variability.
Leks
Assemblages of rival males who cluster together to perform courtship displays in close proximity.
What behavioral life stages do individual bees progress through?
Cleaner-nurse- pollen packer- forager
edge detection
Contrasting coloring patterns that obscure an animal's actual outline.
Describe parental care in blue-footed boobies.
Extensive and shared
Charles Darwin
Idea of divergence from finches
Paternity Uncertainty and Parental Care in Boobies Research question
If a male booby is uncertain about his parentage, will he provide as much care?
Egg Guarding and Opportunity Costs of Parental Care in Frogs Research question
If egg attendance increases hatch success, why don't all males attend eggs at a high level?
Hybridization (genetic variability underlying trait variability)
If hybrids are an intermediate of the two traits, this indicates variability.
Artificial selection (genetic variability underlying trait variability)
If it is possible to increase the expression of behavior over successive generations, then it is heritable and there is a genetic component
Resource Defense
Polygyny is a type of polygyny where the male guards a resource that the female needs for reproduction.
P-value
Result of obtaining a more extreme value if the null hypothesis is true
Circannual
Rhythm that is seasonal. Hibernation even in darkness and constant temperature
Circadian
Rhythm that runs on a 24 hour cycle, adjusted daily by information from the optic lobe
Can altruistic behavior be involuntary?
Yes. Example: Manipulation
Round dance
a dance to communicate the location of food sources close to the colony {less than 35 yards away}.
Polyandry and example
a mating system involving one female and two or more males. Example: honey bees- queen bee mates with multiple males
rachis
a stiff quill
rare pattern: male monogamy. so.... why have male monogamy then?
a)mate assistance b) mate guarding c) female forced monogamy
linkage disequlibrium
both sexes of offspring inherit their respective genotypes. The male trait and female preference become genetically correlated. males evolve even more exaggerated character and females evolve preference for even more exaggerated characters
sunfish parents
builds nests for the females to spawn in, chase off the other males in their territory
Communication
can be defined as any behavior of one animal that ends a signal affecting the current or future behavior of another animal.
Altruistic behavior ______.
can increase an individual's inclusive fitness
what is often used to identify the source of a signal?
comparative approaches
Leks costs and benefits (female)
costs: they must chose a male, care for kids by themselves, might have to compete with other females if necessary/ benefits: Keeps spread of disease to a minimum, they get to "shop" for their partner
Polygyny costs and benefits (male)
costs:.../ benefits: male gets to mate with several females and have more offspring, smaller investment in the embryos, the chance of successful reproduction is higher
In haplodiploidy systems, males have no ___ and ____ but have ____ and ____
dad or sons but have grandfather and grandsons
mutler's ratchet
deleterious mutations will arise at various loci creating a spectrum of genotypes carrying a 0,1,2, ... m mutations. individuals in carry more mutations than their ancestors, but never fewer. the proportion of 0 mutation genotypes will decline over time. in other words, an inevitable decline in superior genotypes. pop. may likely go extinct
disadvantages of recombination
destroys adaptive combinations of genes. also carries the cost of sex. - an asexual pop will produce offspring that are 100% guaranteed to make offspring if they survive to reproductive age. - sexual pop. is not guaranteed offspring reproductive success, even if all offspring survive to reproductive age.
Y linked
determination of a phenotypic trait by an allele (or gene) on the Y chromosome.
Adaptationist
develops & tests hypotheses on the possible adaptive value of particular traits
blended displays
different ratios of fear and aggression -baring teeth and piloerection (raised fur) express aggression -flattened ears express fear -motivational conflict when both of the above occur
superior
different types of sperm and penis selection pressure, bristles on the penis to scrape out sperm from other males
evolutionary models of mates choice
direct benefits models good genes model runaway selection sensory exploitation
Inclusive fitness
direct fitness + indirect fitness
ecological constraints theory
dispersal options for mature offspring
Males on leks defend
display sites
Precocial Definition
don't need mom for long; born with good sight and have little fur and hair
mating systems terminology (categories)
dual monogamy=male and females monogamous exclusive polyandry=female polygamy, male monogamy polygyny=female monogamy, male polygamy dual polygamy (polygynandry)=female and male polygamy
examples of mating systems categories
dual monogamy=prarie vole exclusive polyandry=jacana polygyny=marmot dual polygamy(polygynandry)=turkey
sensory bias
due to organization of sensory organs and neurology, some species have a much stronger neurological response to certain shapes, patterns, or colors than members of other species.
what is a possible explanation for higher degrees of sexual dimorphism in ZW animals (i.e. snakes and birds)?
due to sexually antagonistic genes: males transmit male beneficial Z genes to their sons, but then females have more control over offspring sex
how do x-linked diseases in women represent a genetic mosaic?
e.g. a women with an allele for hemophilia on only one X chromosome would still have 1/2 her liver cells functioning normally (normal function)
When prey are scarce, the bluegill sunfish ______.
eats each prey encountered regardless of prey size
2 flightless birds
emu and emperor penguins
the study of insects
entomology
random mating
equal oppurtunity for mating for both males and females
Which sex controls EPC's?
evidence for female control. ex. superb-fairy wren would sneak out at night so males wouldn't know and would solicit EPC's from males in other territories. look at graph... forays would peak on days when female was most fertile providing evidence that she controlled mating fights and displays, males were seen to be visited that were sires9providing parentage)
What type of adaptive sex ratio bias occurs in mites?
extreme female-biased sex ratio (14 females to 1 male born dead)
Desert ants have true navigation
false
Heritability represents the amount of genetic variation in a population.
false
Male redback spiders don't increase their reproductive success when they are cannibalized during copulation
false
Migratory monarchs return to the same sites year after year as a result of imprinting.
false
Type II male midshipman fish transition into type I males as they age
false
cataglyphis ants use the magnetic field to navigate the featureless desert terrain they live in
false
Leks and example
females search for males; females pick from a group; females raise child. Example: peacock.....
example of exploitation (eavesdropping)
frog mating calls -a calling male Tungara frog may inadvertently attract an illegitimate receiver (i.e., eavesdropper)
females
gametes big, few, and costly -ex. humans: 1 egg per cycle
flock
gather in large groups
units of selection
gene replicators gene selection
Indirect fitness
genes contributed to the next generation by an individual indirectly by helping non-descendant kin (relatives other than offspring)
identical by descent
genes that are shared because of common ancestary
Brood Parasitism
get someone else to conduct parental care who: old world cuckoos, New cowbirds, some ducks, (some insects),
good genes
good genes hypothesis: states that females mate with more than one male because their social partner is of lower genetic quality than other potential sperm donors, whose genes will improve offspring viability or sexual attractiveness.
good genes (indirect benefit)
good genes mean that they can have a lot of offspring, and their good genes would spread through more generations
which types of mate choice boil down to PI and direct benefits?
good parent and good resources
Diploid
have 2 copies of each gene
Eusocial math only doesn't work for
honeybees because evolved to be polyandrous
levels of selection
individual organisms
Brood Parasitism
is the manipulation and use of host individuals either of the same (intraspecific brood-‐parasitism) or different species (interspecific brood-‐parasitism) to raise the young of the brood-‐parasite.
Potential Reproductive Rate
is the maximum number of offspring that each parent can produce per unit time.
Operational Sex Ratio
is the ratio of potentially mating males to fertilize females. It is based on Triver's theory of parental investment.
pair bond
is the strong affinity that develops in some species between a pair males and females. potentially leading to producing offspring.
Territory
is the term for the portion of an animal's home range that it will defend from conspecifics.
5. Reciever's Response
leads to an evolution of a receiver response
damselflies
male's genitalia are adapted to remove sperm of pervious mates from reproductive tract
variation in reproductive success
male: higher, female: lower
What is the heterogametic sex in humans?
males (XY)
operational sex ratio bias
males compete because there are many more males than want to reproduce compared to women. males secure territory, physical and behavioral traits are related to male competitiveness once selected. Agression between males leads to elevated levels of testosterone
Facultative siblicide
means that siblicide may or may not occur,based on environmental conditions.
would it be more productive to have an excess of females, an excess of males, or equal sex ratios in a population?
most productive with an equal sex ratio, but also more productive to have an excess of females rather than an excess of males
ant-acacia mutualism
mutualism in which ants live in thorns of trees and the trees secrete nectar and lipids for the ants
facultative
mutualism in which partners can survive independently but still benefit from mutualism
obligate
mutualism in which partners cannot survive without eachother
Opposite sex twins
no siblicide
direct benefits
occurs when a male provides a direct benefit to a female and her offspring
Monogamous mating system in oldfield mice (Peromyscus polionotus).
one male pairs with one female - no sperm competition with other males. Sperm aggregate indiscriminately.
Polygyny
one male with many females
Niko Tinbergen
one of the founders of Ethology, worked on levels of analysis (4 questions) was invilved in work with gulls studied fixed action periods
Birds that migrate at night ______.
orient to a fixed point in the rotating night sky
Taxis
orientation and movement with directional; directed movement away from a stimulus
Charles Darwin
origins of species; developed the theory of evolution by natural selection 1858
example of mate assistance hypothesis with study
parental care boosts reproductive success in monogamous spotless starlings. -anti-androgen (CA) treated males provide more food to their broods and greater number of fledglings
variables affecting choice of mating system
parental investment needs of the young parental abilities Reproductive synchrony Food availability Predator pressure
true
parental investment, increases offspring's chances of reproductive success
If moving the landmarks in an animal's environment disrupts its orientation, then the animal likely relies on ______ for finding its way.
piloting
What did the Trivers-Willard hypothesis (1973) predict about sex ratios?
predicted that females should produce more sons when resources are abundant, and should produce more daughters when resources are scare
polygyny threshold model
predicts females choice of territories
when mates are limiting
promoted behavior is being less discriminatory and there ends up being greater for mates
3. Adoption of a receiver encoding rule (receiver code) relating the cue and the condition;
receiver makes the connection
coevolution
reciprocal evolutionary adaptations involving both partners of ecologically interacting species (can be difficult to document in nature)
Kin Selection
refers to apparent strategies in evolution that favor the reproductive success of an organism's relatives, even at a cost to the organism's own survival and reproduction
Female Uganda kob do not prefer to visit leks with more males
rejects female benefit? don't just want to look and compare
1/8
relationship for first cousins
½
relationship for full siblings
Intrabrood Conflict
sometimes called "sibling rivalry", is conflict between members of the same litter/brood.
evidence for chase away? give background info on study.
still relatively new model (1998) so evidence is scarce case study: chase away in cricket spermatophylaxes? besides nutritional effect (which is little or none in decorated crickets) many insect ejaculates contain substances that manipulate female reproductive behavior -affect oviposition (reproductive readiness and egg laying) -reduce female attractiveness -anti-aphrodisiacs...female delays remating conflict? --maybe male and female interests not always the same. background: gyllodes species----produce spermatophylax acheta species------don't produce spermatophylax
conditional mating strategies
strategies that help losers mate
A group is said to be eusocial if ______.
the group contains nonreproductive helper individuals
mate guarding
the longer a male may keep away other males, the higher the chance his sperm fertilize most.all of the eggs.
symmetry
the measure of the left and right sides of an organism.
fitness benefit
the positive effect of a trait on the number of surviving offspring produced by an individual or the number of copies of its alleles that it contributes to the next generation
fly away
the route migrating birds fly every year
sexy son hypothesis
the sons of females that choose an attractive male trait have improved mating success because they inherit the trait that made their fathers appealing to their mothers
in what ways do the hearing and eyesight of birds surpass that of humans
their hearing surpasses that of a human in the ability to distinguish differences in intemsity and respond to rapid fluctuations in pitch
proxy cues
there are certain cues that lead to good genes (coloration, ornamentation, symmetry, creativity)
why two gametes?
there are two gametes becasue the sexes have been classified by gamete size
when investment in offspring is greater in males,
there can be increased competition between females.
Obligate Brood Parasites
they are unable to build a nest of their own.
what happens as autonomic signals become ritualized?
they become uncoupled from the source and are used to signal very different types of information
Reflective consciousnes
thinking about thinking
reflective consciousness
thinking about thinking
Harem-Defense Polygyny
this is where a male gathers and defends a female small herd (harem) preventing other males from getting access to her
Operant conditioning
trial and error learning
operant conditioning
trial and error learning
Genetic drift is a mechanism by which evolution occur
true
Niko Tinbergen was a famous ethologist responsible for the levels of analysis.
true
alfred russel wallace developed a theory of evolution by natural selection in 1858
true
one in ten fathers is not the 'real parent'. true or false?
true
polygynandry
two or more males with two or more females
trophic
type of mutualism - partnerships for obtaining energy and nutrients ex: corals and reefs, mycorrhizae and plants, lichens, leaf cutter ant
Sibling rivalry
who should get what resources
it is an evolutionary stable strategy
why is 1:1 ratio selected for?
sexual imprinting
young learn mating preference by watching adults
Why is natural selection a population process?
"Better" traits predominated over time because individuals with that trait have greater reproductive success in each generation
50
% shared alleles designates a full sibling in the coefficient of relatedness.
Manipulation
(Enforced/Manipulated Altruism) The queen kills eggs laid by workers or suppresses reproduction in the workers via pheromones or other chemical signals. The more effective they are at this, the less the workers will waste their energy on producing eggs.
Altruism
(Self-sacrificing behavior) Behavior that has a fitness cost to the individual exhibiting the behavior and a fitness benefit to the recipient of the behavior.
Krebs and Davies (1993) definition of communication
(behavioral ecology perspective) "the process in which actors use specially designed signals for displays to modify the behavior of reactors" *behavior of reactors
Brandbury and Vehrencamp (1998) definition of communication
(ethological perspective) "the provision of information via a signal by a sender to help a receiver make a decision. In true communicaion, both the sender and receiver benefit" *in true communication, both the sender and receiver benefit.
Wilson (1975) definition of communicaion
(sociobiological perspective) "communication occurs when the action of or cue given by one organism is perceived by and thus alters the probability pattern of behavior in another organism in a fashion adaptive to either one or both of the participants." *adaptive to either one or both of the participants
the classic comparative approach:
(was used by Darwin to build his case for evolution) is used to demonstrate the existence of logical series of steps in trait elaboration among a group of extant (existing) species. -a well-known communication signal that was examined in this way is the courtship display of the peacock.
Female guppies preference for orange spots on males
*read in text Criteria 1, 2, 3 not known but 4 appears to be met.
Circadian
- 24 hour solar cycle
In what way can gobies result in a decrease in bass fitness?
- Bass living in areas containing gobies spend much higher energy guarding their eggs than do fish living in areas with no gobies - The presence of nest predators may result in a decrease in bass fitness because of higher energy costs of guarding
Interspecific brood parasites
- Lay eggs in the nest of another species - Egg rejection is reduced by evolution of eggs that match size, colour, and shape of host eggs
Classical conditioning
- associational learnin
True navigation
- compass and map orientation, knowing where you are in a global sense not just local
Biological clock
- internal cyclical rhythms that persist in the absence of external stimuli
Perceptual consciousnes
- thinking about your environment
Dissociated effect
- uncoupling of behavior and hormonal activity
Alpha level
- what percentage statistically significant usually .05, .
pure epigamic selection
-->boils down to PId direct benefits
Resource holding power
-Ability of an animal to win a fight -Territorial animals higher quality -Territory is more valuable to holder than new comer
Ideal free distribution and despotic distribution
-Gall aphids -Can be 2nd on big leaf or 1st on smaller -Within leaf: despotic distribution Between leaves: ideal free distribution
Unforced honesty
-Goals of sender and receiver congruent -Both benefit (like honeybee waggle dance)
human sexual selection: mate competition
-Human demography patterns suggest an evolutionary history of male-male competition... revealing that males are always larger than females! *potential evidence for mate competition -There exists a sexual dimorphism in longevity--females live longer than males -Male mortality peaks during the "reproductive competition" years--ages 15-35-->higher rate of dying by external source *could be due to mate competition
Coevolution
-Influence of closely associated species on each other in their evolution -Continually increasing diversity and complexity
Timing of Gene Activity
-It's a combination of genetics and environment -if the birds lack the necessary neural network or the appropriate genes they won't sing -if they lack the proper environment they may not sing the appropriate song
Testosterone Activational
-Male sex drive
Ideal free distribution
-Number of individuals that aggregate in various patches is proportional to amount of resources -Blackcap warbler
Dilution effect
-Safety in numbers -Chances of individuals being selected negatively related to group size -Assumes equal probability of capture for all group members
Resource partitioning
-Similar species exploit limited resource without one going extinct -Each species adopts a pattern of usage that is not competitive
Why might consciousness be adaptive for highly social species?
-Social Brain Hypothesis: attribute mental state to others to predict their behavior -Machiavellian intelligence: large human brain grew because of intense competition for reproduction
several types of behaviors may arise form motivational conflict:
-ambivalence behavior -displacement behavior -redirected behaviors -other displays
auditory communication o f the Chestnut Sided Warbler
-call/sing for territories and mating -1/2 chicks aren't fathered byte guy who is taking care of them -songs indicate which male is best to mate with
sexual selection
-differences among individuals of a sex in # of mates obtained -differences in the reproductive capacity of individuals of a sex -competition among individuals for access to mates/gametes
auditory communication of Elephants
-elephant rumbles -females live in groups -rumbles exchaned more often with strangers than familiar friends-->to introduce themselves -pick up vibrations (from elephant rumbles) through gourd-->and also auditory stimulus
chase away selection
-female preference then evolves away from male traits if there is a cost to being exploited. viability selection on female sensory system-----> female attraction for male trait that is absent------> mutation produces a rudimentary male display trait--------> female fitness declines when female fitness declines begin loop: female fitness declines----> female mating threshold increases----> male attraction declines---->exaggeration of male display------>back to female fitness declines
good genes theory
-females prefer courtship displays and ornaments (traits) that are indicative of male viability -adaptive value: offspring may inherit the viability advantages of the father female choice fro indicators of health, which may also be related to good genes?
ritualization leads to what?
-leads to co-evolution between sender and receiver -may lead to emancipation of signal from condition that gave rise to the original cue
Runaway sexual selection ("sexy sons" hypothesis)
-male display character and female preference reinforce each other so that both evolve to be more extreme --> genetic correlation of trait and preference -female choice does not benefit survival of offspring but increases mating chances of sons because the females are selecting for males with best traits -once initiated it becomes self-reinforcing (or runaway) -drives sexual selection without considering ecological costs -helps explain why sex ratio is 1:1 in most cases (females want sexy sons)
sensory exploitation hypothesis
-male evolves display trait that exploits pre-existing sensorybias in femal -makes unique prediction that phylogeny, female bias (preference) existed before male trait
Differences between males and females and their bird-songs
-males sing complex songs -females sing simple call notes
Evidence for honest courtship signals in damselfish
-males that display at higher rates attract more egg-laying females -males with higher display rates are better parents
What did Bill Hamilton propose about local mate competition and sex ratios?
-many animals grow up with close relatives and mate with them (inbreed) -instances of inbreeding favour a female-biased sex ratio because brothers will fight with each other and compete for mates and resources (the mothers energies are wasted)
2. predator defense
-neighbor males more likely to help against predator if they copulated with resident female so... females gain nest defense!
Adaptive effects of sexual selection
-possibility that sexual selection decreases mean fitness of populations (runaway selection--> ecological disadvantages) -alternative possibility that sexual selection help purge deleterious mutations from populations (good genes model)
Sensory Exploitation
-proposes an entirely different processes of signal evolution -receivers have latent preferences that can be exploited by manipulative senders to create new signals
Tutors
-reared sparrows in soundproof rooms -listened to tapes of sparrow songs Result: -eventually the young sparrow would reproduce the exact songs he had heard on tape -by 200 days of hearing the same songs, the young birds would sing the exact song they had heard *there is a critical window of 10-50 days when the young bird must hear songs from its tutor
exploitation (eavesdropping)
-receiver benefits but sender does not!
ritualization
-refinement of an inadvertent cue into a signal -requires fitness benefits to sender -involves: simplification, exaggeration, repetition, and stereotyping to improve information transfer of the signal
Song recognition
-sparrows that listen to songs of other species tended to produce aberrant songs like the ones that had heard no songs at all -young sparrows can aquire songs from taped tutors even if the song is played in reverse -male white-crowned sparrows are predisposed to learn their own species song -window of 10-50 days
2. withhold a signal
-such as a signal that indicates alarm or food location ex: Rhesus macaques will withhold food calls when food is discovered unless relatives are nearby
auditory communication in bees
-tell others 3 dimensions of where good food is; how far out, over and up into the forest -bees can be trained to forage in any specific place int eh forest because they communicate to each other -they can communicate how high a food source is (height) -also can communicate direction and distance *direction, distance, height
Female defense polygyny in siphonocetine amphipods
...
Female defense polygyny in tropical bats
...
Fertility insurance hypothesis in Gunnison's prairie dogs (Hoogland)
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Fertility insurance hypothesis in red-winged blackbirds
...
Polygyny threshold model in lark buntings (Pleszczynska & Hansell)
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Promiscuity in chimpanzees
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Sexy-son hypothesis in sandflies (Jones)
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Which results from Drosophila experiments demonstrate a mechanism for adaptive phenotypic variation in the Y chromosome?
1) Y chromosomes have substantial polymorphic variation for genes that differentially affect X-linked and autosomal genes 2) affected genes are more highly expressed in males, and more subtly expressed in females 3) affected genes act on microtubule stability, lipid and mitochondrial metabolism and thermal sensitivity to spermatogenesis
2 nuclei involved in cong learning
1) anterior neostratum (IMAN) 2) Area X
Variety of events that influenced the gene pool of white-crowned sparrows
1) random mutations 2) loss of genetic variation 3) random genetic drift 4) natural selection acting on other features than songs
how is a sex chromosome produced?
1) starts off as an autosome 2) acquires a sex determining factor (i.e. SRY in humans) 3) selection operates to reduce/stop recombination at this sex determining factor (crossover suppression)
model of signal evolution. the process of signal evolution (model) involves five initial steps (or links):
1. Association between a sender-produced cue and a condition 2. Perception of the cue by the receiver; 3. Adoption of a receiver encoding rule (receiver code) relating the cue and the condition; 4. Association between updated information and the development of a receiver decision rule: 5. Receiver's response; leads to an evolution of a receiver response.
What are some ways that alternative foraging strategies persist in the same population?
1. Frequency dependent morphs 2. Individual condition (subordinate vs dominant)
Theories to explain attraction despite lack of nuptial gift or parental investment
1. Healthy Male Theory 2. Good Genes Theory 3. Runaway Selection Theory
Reproductive egg laying tactics (3)
1. Non-parasite: lay all eggs in her own nest 2. Pure parasite: lay all eggs in the nest of other females 3. Mixed strategy: Lau some eggs in her own nest and some in the nest of others
four major components of communication
1. Sender= the individual producing the signal 2. Receiver=the individual to hwole the signals is directed 3. Transmission Channel= sensory modality (auditory, visual, olfactory, electric) 4. Signal=???
the two models of receiver pre-adaptation:
1. Sensory drive (Endler 1992) 2. Sensory Exploitation (Ryan 1990)
4 Post-copulatory strategies.
1. Spines can remove sperm from other males. 2. Larger testes produce more sperm. 3. Sperm cooperate to increase swimming efficiency. 4. Males prevent subsequent matings.
9 characteristics that equip birds for flight
1. a compact light weight and very strong skeleton 2. a rigid backbone 3. hollow spaces in the skeleton 4. bipedal anatomy which leaves the wings free for flying 5. a prominent ridge or keel on the breastbone 6. 3 bones on the shoulder area to support each wing 7. light weight beaks and skulls 8. an efficient circulatory system including a 4 chambered heart 9. powerful muscles to power the wings during flight
why do females with EPF's have higher success at raising their offspring?
1. access to food 2. predator defense 3. polygyny
Why might an animal not always be able to do what seems best?
1. being able to do whats best (optimal behavior) depends on what everyone else is doing (game theory) represents that what the animal is doing may to avoid the worst outcome even if it means its not the best outcome or option
Who benefits in communication in cases when only one benefits (not true communication) list the two types
1. deceitful communication (manipulation) 2. eavesdropping
consequences of mating system variation
1. differences in intensity of sexual selection 2. males tend to seek quantity while females tend to seek quality 3. evolution of sexually selected traits
why should interspific brood parasite hosts accept eggs that obviously are not their own?
1. evolutionary lag 2. cost of rejection may outweigh benefit 3. cuckoos may retaliate against rejectors
universals of attractiveness. list them.
1. facial symmetry and body shape 2. look-alikes 3. parental traits and fidelity
list the four parts of mate choice
1. good looks 2. good genes 3. good parent 4. good resources
What type(s) of polygyny do humans practice??
3. Resource defense-- occurs when males defend resources that attract females. (often female choice initiated)
nictitating membrane
3rd eyelid
Warbler Microhabitats
5 species of warblers all eat similar prey but utilize different part of the trees they live in enabling optimal eating for all species
Mother daughter relatedness
50%
Mother relatedness to son is
50%
father daughter relatedness
50%
polyandry=
=females have >1 mate during breeding season
3. Autonomic processes =
=involuntary processes of the autonomic nervous system of vertebrates that control the heart, blood vessels, lungs, intestines, eyes, and certain glands
polygyny=
=males have >1 mate during breeding season
principles of antithesis=
=signals with opposite meanings (aggression vs. submission) should have opposite or contrasting form to make meaning clear Darwin (1873) was the first to recognize the displays (Antithetical displays)
definition of cues
=stimuli that also carry information but they have no benefit to the sender ex: an owl finds and attacks a mouse as a results of the inadvertent sounds (cues) the mice produce when foraging.
1. Facial symmetry
=the extent that the left half of the face is the same as the right -symmetry is thought to be a measure of the ability of an organism to cope with environmental stress. -only high-quality individuals can maintian symmetric development under environmental stress -therefore symmetry can be an indicator of "good genes"
Motivational Conflict: other displays Other Displays= give context example
=used by sender in another context to elicit the same type of response by receiver example: senders in aggressive contexts can deflect the attention of rivals by stimulating a non-aggressive motivational system in the receiver
altruism
A behavior that has a fitness cost to the individual exhibiting the behavior and a fitness benefit to the recipient of the behavior.
crypsis
A behavior, color or shape that makes an animal difficult for predators to detect.
Brood parasitism
A behaviour in which a female (brood parasite) lays an egg in the nest of another female, e.g. common cuckoo.
Cryptic Female Choice
A form of sexual selection that arises after mating, when females store and separate sperm from different males and thus bias which sperm they use to fertilize their eggs.
Sperm Competition
A form of sexual selection that arises after mating, when males compete for fertilization of a female's eggs.
Sexy-son hypothesis
A hypothesis that females select among males based on genetic traits in the males that will lead to the production of sons that are attractive to the opposite sex
Mertensian mimicry
A lethal organism could be the mimic of a less harmful organism (model).
Semelparity
A life history strategy in which reproductive occurs once in a lifetime
Iteroparity
A life history strategy in which there are multiple reproductive events throughout the lifetime
hotshot (referring to leks)
A male whose attributes are especially appealing to sexually receptive females. Hotshot hypothesis: a tentative explanation for why males cluster their display territories in a lek. The clustering is said to occur because subordinate males are attracted to dominant individuals that are especially appealing to females, in order perhaps to gain sexual access to some of the females.
Monogamy
A mating system in which one male pairs with one female. This is very rare and occurs when each male mates only with a single female, and vice versa. Social monogamy occurs when a male and female form a stable pair bond and cooperate to rear the young, even if either or both partners sneak extra-pair copulations. This occurs in a few fish, insect, and mammal species, and in almost 90 percent of bird species.
Polyandry
A mating system where females mate (or attempt to mate) with multiple males.
coefficient of relatedness
A measure of how closely the actor and beneficiary are related. Also defined as r.
Promiscuity
A member of one sex within the social group mates with any member of the opposite sex.
Egg attending
A method of parental care in which one parent remains near the eggs to protect them from predators and remove infected or dead eggs.
Determinate growth
A pattern in which individuals stop growing at some point in their life
Red Queen Effect
A phenomenon seen in coevolving populations - to maintain relative fitness, each population must constantly adapt to the other. Leigh Van Valen borrowed the tale of the Red Queen from Lewis Carroll's Through the Looking-Glass and compared her difficulties to those is biological arms races, such as between parasites and their hosts.
Red Queen Effect
A phenomenon seen in coevolving populations - to maintain relative fitness, each population must constantly adapt to the other. such as between parasites and their hosts.
polygyny
A polygamous mating system involving one male and many females. Male bonds with multiple partners at once. The most common mammalian mating system.
Which of the animals listed below would not be expected to have an endogenous circannual rhythm? A groud squirrel that hibernates, a white-tailled deer living in eastern North America, a cave salamander, a migratory bird that summers in North America and winters in equatorial South America, or all of the above.
A white-tailed deer living in eastern North America
dilution effect
Aggregation of animals to reduce the chance of being attacked by a predator. i.e. If 5 birds each eat 2 butterflies a day, the risk of death for a member of 1000 butterflies is 1% whereas in a group of 100 butterflies it is 10%
Mobbing Calls
Alarms that signal conspecifics to join together to defend a resource or a member.
Why does altruism seem paradoxial?
Alleles that cause an organism to behave altruistically should be selected against since these alleles should lower the organism's fitness.
What is the basic process underlying a genomic microarray experiment, as it relates to the behavior of an animal (like mate preference behavior in swordtails)
Basic steps 1. conduct trials to elicit mating behavior 2. extract brain, look at gene expression (mRNA) 3. Identify genes differentially 4. look for genes only expressed in certain social situations 5. identify "annotated" genes, pick those relevant to your behavior 6. use qPCR to quantify expression of candidate genes during behavior
Why can biased operational sex ratios generate strong sexual selection?
Because the abundant sex (typically males) must compete over access to the limiting sex (typically females).
Parental care
Behaviours by a parent to enhance the fitness of offspring, including incubation, feeding, and defense
Direct Benefits
Benefits that affect a particular female directly, such as food, nest sites, or protection.
Indirect benefits of being choosy.
Benefits that affect the genetic quality of a female's offspring, such as male offspring that are more desirable to females. Showy ornaments, Genetic compatibility.
Indirect Benefits
Benefits that affect the genetic quality of a particular female's offspring, such as male offspring that are more desirable to females.
Deceit
Benefits the sender at the cost of the receiver
Hamilton's rule states that analruistic allele could spread in a population if Br>C, where B represents the fitness benefit to the recipient, r is the coefficient of relatedness between altruist and recipient, and C represents the fitness cost to the altruist. If r=0.5 between the altruist and the recipient, what would the ration of costs to benefits have to be for the altruistic allele to spread?
C/B<0.5
Tests of Polygyny Threshold Model
Cavity nests limiting for normally monogamous prothonotary warblers. Prediction: territories supporing greater resources should result in polygyny. Method: a)supplement territories with nest boxes b)Examine resulting mating system in territories. Result: Males on territories with added nest boxes were more likely to be polygynous
types of camouflage
Countershading, background matching, brokenness, disruptive coloration, changing colors and patterns
convergent evolutions
Distinct ancestry and different genetic heritage under similar selective pressures evolve similar behaviors.
Obligate brood parasites
Do not nest themselves and only lay eggs in the nests of other species
Prolactin and Maternal Care in Rats (Bridges et al. 1990) Research question
Do prolactin levels affect parental care?
Hatch Asyncrhony and Brood Reduction in Blackbirds (Forbes et al. 2002) Research question
Does hatch asynchrony affect offspring mortality?
Give a one man example of resource defense polygyny
Donald trump.. -he had 3 children with his first wife Ivana, one with 2nd wife Marla Maples, and another with recent wife Solvenian model Melania Knauss Hugh Hefner... He had 2 children with his first wife, and 2 with playmate Kimberley Conrad who he married in 1988 at the age of 62!
Motor neurons
Efferent CNS---> glands/muscles
What do people mean why they say "there is a gene for behavior X"?
Either there is a gene that influences X in some way. Or there is genetic variation underlying variation in X.
What is a situation which offers the lowest "opportunity for selection" for males?
Every female chooses one male to mate with for life.
Sexual conflict:
Evolution of phenotypic characteristics that confer a fitness benefit to one sex, but a fitness cost to the other sex. Adaptations that arise due to sperm competition can harm the female. As a result, females have counter defenses to males. Traits coevolve antagonistically.
Intrasexual Selection
Female choice
runaway sexual selection
Females have a preference for one thing, and then it spirals out of control. both the physical trait and preference for the trait are passed on. The population shifts so that most males have long tails and most females prefer long tailed mates. Once this has happened, the process may run out of control.
Good genes hypothesis
Females mate with more than one male because their social partner is of lower genetic quality than other potential sperm donors whose genes will improve offspring viability or sexual attractiveness
Antipredatory behaviors Detection
Immobility Crypsis
Receiver
Individual that is receiving message
Signaler
Individual that is sending the message
Level of selection
Individuals (interactor)
Sequential polygyny
Individuals forming many short-term pair bonds in sequence during a given breeding season
Hermaphrodites
Individuals that produce both female and male gametes.
Biological clock
Internal, cyclical rhythms that persist in the absence of external stimuli
Polygamy
Is a mating system with more than one partner. Has three types: polygyny, polyandry, polygynandry
Parental Care Tradeoff in Treehoppers (Zink 2003) Research question
Is there a relation between the number and size of an egg clutch a female can produce and the amount of guarding behaviour she engages in?
mimicry
Is when one species evolves to look, sound, smell or act like another species.
Weaknesses of ESS
It always remains to be seen whether during the course of evolution, the ESS will actually become established at all.
what is sex
It's biparental It's meiosis & syngamy It's genetic variation
Based on the theory of reciprocal altruism, predict the conditions under which people are expected to donate blood.
People would be expected to donate blood under two conditions: (1) They either received blood before or expect to have a transfusion in the future and/or (2) they receive some other benefit in return, such as a good reputation among people who might be able to help them in other ways.
Two Experiments
Petit 1991: 1. added nest boxes in the flooded riparian and dry bottom land habitat 2. varied nest box density in flooded riparian habitat \ results of exp 1: nine bigamous parings in flooded habbitat. costs of bigamy were comparable to costs of settling in dry habitat results of exp 2: females settles earlier in territories with more nest boxes. males with more nest boxes were more likely to be polygynous
human sexual selection: Mate Choice What are the adaptive mate preferences of men and women?
Physical appearance is important to humans -there appear to be ceratian features/traits (aka universals) that are found attractive across cultures
What are the different ways that forced honest communication can evolve?
Physical constraints (lying isn't possible) Handicap principle
• Describe the remarkable mating system diversity among dunnocks, and some factors which influence which system is adopted by individual birds.
Polygynandry and polygyny -Females compete for male parental care Polygynandry and polyandry -Males compete for copulations Males more fit with polygyny Females more fit with polyandry Ecological factors - Settle in dense cover -Feed small prey to offspring
Genetic Drift
Random change in allele frequencies in a population, especially a small one
conspicuous
Standing out as to be clearly visible
What can males often fighting with each other over access to females generate?
Strong sexual selection for large body size, weapons, and aggression.
Hatch asynchrony
The hatching of offspring in a clutch of eggs on different days
Activational effect
Triggering, short term, reversible. -Seasonal sexual behavior
Promiscuity vs Polygynandry
as with polyandry, we can distinguish between genetic patterns and a social system promiscuity: if males and females each mate with multiple partners without any kind of social bond, some researchers call the mating system "promiscuous" polygynandry: cohesive social groups form. that include multiple males and females who mate with multiple partners of the opposite sex, some researchers call this "polygynandry"
ritualized display of male stickleback that incorporates alternation between two systems:
attacking female vs. leading her nest come to my nest and mate, get out my territory or i'll attack come to my nest and mate
Motor neurons-
carry from CNS to glands/muscles
classic example of motivational conflict: redirected behaviors
classic example= case of grass pulling in fighting herring gulls which appear to seize and pull on clumps of grass as if they were pulling the wings of their opponents.
sperm competition
competition between the sperm from two or more males fo fertilize the eggs of a signle female during one reproductive cycle.
asymmetrical competition
competition that results in skewed higher fitness to one segment of a population at the expense of the remainder of the population.
sexual conflict
conflict b/w the sexes over decisions that differentially affect their fitness, such as how much to invest in offspring and whether or not to mate
3 types of feathers and the purpose of each
contour: aid in streamlining flight: necessary wing shape for flight down: provide excellent insulation w/o adding much weight
How does the environment affect sex determination in many reptiles?
cool conditions determine sex in turtles and tortoises, while warm conditions determine sex in lizards and alligators (removes the need for sex chromosomes and should thus reduce gender load)
females choosing mates should favor courtship signals that are _______ to displaying males, and ______ in a way that tests mate _________. give examples.
costly costly suitability examples: -male damselfish display rate correlates with parental care -house finches signal with carotenoids
haplodiploidy
females are more related to their sisters than to their own offspring (0.75), because full sisters inherit exactly the same genes from their father. diploid (0.5)
How is Y chromosome polymorphism demonstrated as a strong determinant of male fitness in Drosophila?
fertilization success of males reverted from high to low in different genetic backgrounds, demonstrating varying polymorphism in the Y chromosome (Chippindale and Rice 2008)
How was the Trivers-willard hypothesis proposed in billionaires?
male biased sex ratios among billionaires implies that parents had higher abundance of resources, and so produced more sons
Polygyny
many females per male who: fish, amphibians, grackles (birds), icertrids, preococial birds, predominant in mammals, lek-mating species
Why do mitochondrial DNA tell a difference story about genetic evolution than Y chromosome genes?
mitochondrial DNA are cytoplasmically transmitted, generally from the female
monandry
one father
Honey bees are
polyandrous (multiple fathers)
semelparous
single reproductive episode before death
intentional movements: aggressive displays often reflect attach preparation movements
the preparatory phases of attack behavior usually become ritualized in threat signals examples: -direct stare -a tensed and forward body posture -the baring of teeth, norms, claws or other weapons -the protection or pulling back of sensitive body parts such as ears *think dogs as an example (see slide for picture)
what is ritualization?
the process for the refinement of an inadvertent cue into a true signal -requires fitness benefits to sender
so what is communication?
the provision of information by a sender to help a receiver make a decision. *see flow chart from sender to receiver in notes.
recombination
variation of genetic traits. - gives offspring higher probability of inheriting rare, disadvantageous alleles.
Paternity Uncertainty and Parental Care in Boobies Methods
• Removed pair-bonded males during part of the fertile period of females • Control: removed males when female fertility was low
Examples of life history traits
• Sexual maturity • Number and size of offspring • Level of parental care • Survival rate throughout lifetime
Prolactin and Maternal Care in Rats (Bridges et al. 1990) Methods
• Treated all individuals with bromocriptine to suppress endogenous prolactin secretion and removed ovaries • Primed females with progesterone and estradiol to mimic pregnancy • Examined behaviour of females treated with prolactin or sodium-chloride bicarbonate (control) • Placed three unrelated pups in the cage with the female and recorded parental care behaviours for six days: latency to contact pups, whether pups were retrieved and carried to the nest, crouching behaviour (huddling)
Parental Care Tradeoff in Treehoppers (Zink 2003) Methods
• Uniquely marked females • Measured the size of egg masses every two days and recorded whether female was present or had abandoned them • Calculated hatching success: the number of nymphs observed on the leaf divided by the estimated number of eggs in a clutch
Conspecific Brood Parasitism in Ducks (Ahlund & Andersson 2001) Methods
• Used egg albumin protein fingerprinting to identify maternity of eggs and hatchlings • Nests were monitored to determine egg laying • Marked chicks and recorded survival
• Using examples in your text, discuss three hypotheses as to why males might accept a monogamous mating system.
• mate assistance • mate guarding • female enforced
Intersexual selection.
Female choice for male traits.
Tropotaxis
Simultaneous comparisons with paired sensors
model/mimic
toxic species/harmless species
Females can make __ gamete and males can make __
females = 2 males = 1
Direct Fitness
Derived from an individual's own offspring. Example: Parents can increase their direct fitness by spending resources to ensure the welfare of their offspring.
What are the main differences between active pursuit predators and sit-and-wait-predators?
Active -Finding, chasing, subduing -Group hunting Ambush -Finding good ambush site, luring/trapping prey
lek polygyny
"arena mating". Make mini territories and show up at the display ground and wait for females to come to them. Eg turkey
What do differences in origin of the first "mitochondrial eve" and "Y adam" suggest about reproductive success?
"mt eve" thought to have evolved long before the "Y adam", which may reflect a difference in variation of reproductive success
Bateman's Principale
"sperm is cheap" males: more mates they had, more offspring they produced females: did not gain any more offspring for having more mates
Runaway Selection Theory
(Reason for Mate choice without material benefits) - Hot dad = hot son --> males with preferred heritable trait ensures male offspring will be sexy - good genes and healthy mates theory likely precedes runaway selection because the trait is currently selected for sexiness
What can asexual animal lineages evolve?
Adaptations enabling them to compensate for the lack of sex.
Another case study for sensory bias/exploitation: Showgirl headdresses on zebra finches
*read in text (Nancy Burley & Rich Symanski) -Background work revealed legband color makes a difference -None of relates have crest still much unknown: -why prefer white crests? -->These birds preferentially line nests with white feathers. (perhaps to conceal white eggs?) Test: do finch species that don't line nest with white feathers also show white crests?
Brood Reduction in Fur Seals (Trillmich & Wolf 2008) Conclusion
Brood reduction is a function of food availability.
Indirect Fitness
Derived from helping relatives produce more offspring that they could produce on their own.
Evolution
Descent with modification (change in gene frequency)
Noctuid moths: preadaptation for??
- greater than 200,000 species of moths - approx 50% have ears (92,000) -ears probably evolved solely for detecting predators -->moths that respond to approaching bats have about a 50% chance survival Noctuid moth ears: -Most moths have 2 auditory receptors (A1 and A2) -Both A1 and A2 are sensitive to ultrasound -Kenneth Roeder (1966) proposed that A1 evokes "far bat" behavior, while A2 evokes "near bat" behavior
Differences in the RA between male & female zebra finches
- in zebra finches, males produce elaborate songs while females produces a few notes -expect males to have differences in song center compared to females -in males: *size of these areas also changes seasonally *ex: in white-crowned sparrows the HVC becomes larger as photoperiod gets longer *from 10-60 days after hatching the male's number of neurons increase & female's decrease
Polyphenism
- phenotypic differences between generations that are environmentally induced
Circannual
- seasonal cycle
Proximate explanations of why genetics and environment affect bird song
- song development depends on structures present in the nervous system -structures require both genetic info and environmental inputs
Behavioral genomics
- study of behavior based on genetic factors and inheritance
Arms Race
-Antagonistic Coevolution -Evolutionary struggle between competing, co-evolving species
Diminishing returns
-As resources are used, they become harder to find -Benefits gained become less than energy invested
Classical conditioning
-Associational learning -Neutral signal before reflex -Important for environmental variability -Aplysia example (siphon tickling and tail shocking)
The attractiveness of averageness. explain.
-Averageness is how similar a face is to everyone else in a population... -average faces are difficult to recognize in a crowd but are aslo surprisingly attractive. picture example on slides: the faces are blends--the more faces in the blend the more average and more attractive. -it is thought that humans also make an average face in their brain--a face that represents the average of all the faces a person has encountered!
Confusion effect
-Can be difficult to select one prey item from a large group -Lower prey capture -Odd individuals singled out
Despotic distribution
-Competition forces optimal territory sizes -Lizards, Great Tits
Red Queen
-Constant cycling of adaptation and counteradaptation
Parasitoid
-Consumer lays eggs on host -Larvae grow up inside living host; kill it in the end
Constitutive defense
-Defense that is always present
Testosterone Organizational
-Development of secondary sex characteristics -Sex differentiation -Timing/dose are critical -Small doses can have long lasting, irreversible developmental effects
auditory communication in bats
-Elizabeths bat detector--> s0 humans can hear bat calls for echolocation
Cuckoo example of deceitful communication (manipulation)
-European cuckoo chick's begging call matches that of four baby reed warblers -this stimulates more frequent feeding by its host parents
Ultimate explanations of why genetics and environment affect bird song
-Evolutionary origin of proximate mechanisms for learning species-specific song? -sparrows learn & sing species-specific songs to find mate -song-learning occurs only in 3 orders of birds; all others produce innate songs
Male mating strategies
-Female defense -Resource defense -Scramble competition: males don't attempt to defend territories, rather they search for receptive females and try to mate with whomever they encounter -Lekking: defense of a traditional display site that females visit to select a mate from among the several to many males displaying on the small, resource-free territory
Frequency Dependent Strategies
-Foraging efficiency depends on what others are doing in a frequency dependent fashion -Usually more rare is favored
Forced honesty
-Goals of sender and receiver incongruent -Deceit is impossible -Communication reveals sender's state or condition honestly
Predicted settlement order under the polygyny threshold model
-Goes in order of reproductive success...doing best they can given the options they have
Selfish herd
-Group so predators will attack person next to you -Assumes unequal probability of capture for group members
Aposematism
-Highly obvious appearance of an unpalatable organism -Likely evolved from non-deadly attacks
evolution
Descent with modification, gene frequency change
Mate choice copying: a mechanism of highly skewed reproductive success
-Highly skewed reproductive success on leks -Proximately, skewed reproductive success might result from mate-choice copying -Females mate with males they see other females mating with (in some cases, older females mate first and younger females copy their mating decisions -Top ranked male black grouse obtained 80% of all mating success on the lek! High variance, high sexual selection on these leks Maybe this happens because older females who "know what's right" shows other females who the better male is
Why do males cluster at leks?
-Hot spot: males cluster when encounter rates are high w/females -Hot shot: clusters form around attractive males (to test this, remove the alpha male, the sexiest male, and if they are staying there, may be a diff. reason) -Predator dilution: males cluster for safety (everyone doing dumb things together) -Female benefit: females prefer to mate at particular sites or with males in clusters either for their personal safety or to compare males (maybe they want to compare males, maybe it's safer for THEM, etc. Females may be driving this whole thing)
Benefits of activational level of testosterone
-Increased attractiveness -Increased territory size -Increases sperm -Increase offspring
Cost of activational level of testosterone
-Increased metabolism (energetic cost) -Reduced survival -Suppression of immune system -Reduced parental care
4. Lek polygyny
-Males fight to control small display area -a lek is defined as an aggregation of males, each seeking to attract a mate, that is not associated with a key resource. -read in textbook about hotspot, hotshot, and female preference hypothesis for leks!!!!!!
Who developed the term "lyonization" and what does it mean?
-Mary Lyon -inactivation of 1 of 2 copies of the X chromosome present in female mammals -the inactive X is silenced by its transcriptionally inactive structure (heterochromatin)
The monogamy paradox: Why would any male restrict his efforts to fertilizing just one male?
-Mate guarding: females are hard to find -Mate assistance: extra offspring outweighs cost -Female-enforced: females refuse to mate with already-mated male or chase off other females
Long term potentiation
-Neuronal mechanism behind classical conditioning -Strengthen synaptic connections -Based on recent patterns of activity -Produce long-lasting increase in signal transmission between two neurons
Giving-Up-Time
-Optimal GUT is where slope of energy gained vs total time is steepest
Conditional Strategies
-Optimal foraging strategy differs based on individual condition
How do monarchs orient during migration, why do they migrate, and why is this example perplexing?
-Orient using UV clock and polarized light -They migrate south to avoid cold Canadian winters and for milkweed -Unknown how they find the same overwintering spot every year
Polyphenism
-Phenotypic differences between generations that are environmentally induced (no genetic basis)
Unprofitability advertisement (pursuit-deterrent signal)
-Prey communicates that it cannot be easily captured -Prey benefit: does not have to outrun predator -Predator benefit: saves time and energy
Inducible defense
-Produced in reaction to damage or stress caused by herbivores
What are the potential costs to hiding from prey?
-Reduces time spent foraging -If caught, unlikely they will escape
What are potential costs to fleeing from predators?
-Reduces time spent foraging -Reduces reproductive success
Batesian mimicry
-Resemblance of palatable organism (mimic) to unpalatable one (model) -Fewer mimics than models
Crypsis
-Resemblance of palatable organism to its environment -Behavior corresponds with appearance
Mullerian mimicry
-Resemblance of two or more unpalatable organisms to each other -Mimics and models are interchangeable
Why does the GUT model apply to starlings, but not honeybees?
-Starlings deliver larger loads to more distant nests -Bees carry less pollen when it will increase their efficiency
Stabilamenta
-Thicker, more noticeable part of a spider's web -Cost: increase predation -Benefits: more insects, avoid wrecking by birds
Operant conditioning
-Trial and error learning -Reinforcement or punishment after a behavior -Strengthening or weakening voluntary behavior
Sensory filtering
-ability to close-tune out certain information that is irrelevant only listen, see, smell what is important for survival
Honest signals or traits may indicate direct benefits such as:
-access to good food or territory -be in the form of nuptial gifts (ex: Mormon cricket protein sac thing) -parental effort or ability
several types of behaviors may arise from motivational conflict:
-ambivalence behavior -displacement behavior -redirected behaviors -other displays
Song Practice
-at about 150 days, male birds begin to produce a variable exploratory "subsong". Must be able to hear himself sing -if deafened during this time, he cannot match his song to that which he learned from a tutor -aberrant song is a result
Proximate explanations for differences in bird-song
-birds differ genetically -differences in the nervous centers that control speech -birds learn different song dialects from other birds
Examples of blending
-blended displays: with different ratios of fear and aggression -broadside threat display: seen in encounters between rival males of many species.
1. emitting false signal. give example.
-bluff or exaggerate ex: mantis shrimp will threaten after molting when vulnerable. -lie (false signal) ex: false alarm call at rich food resource
Universals of Attractiveness: 3. Parental traits and Fidelity
-both men and women place high value on one trait: fidelity -cornell study asked nearly 1,000 people age 18-24 to rank several attributes, including physical attractiveness, health, social status, ambition, and faithfulness, on a desireability scale -people who rated themselves favorably as long-term partners were more particular about the attributes of potential mates. After fidelity, the most important attributes were physical appearance, family commitment, and wealth and status. "good parenting, devotion, and sexual fidelity- that's what people say they're looking for in a long-term relationship"--Stephen Emlen
Ringed plover example of deceitful communication
-broken wing display -heterospecific communication: sender communicates vulnerability to foil potential predators.
green turtle courtship behavior
-circle first in courting -male competition is extreme -males lock onto females back -other males try to beat male with woman -bunch of rival males attack and get aggrivated so they start fighting each other, allowing the couple to escape unnoticed.
what causes displacement acts??
-considerable disagreement, but two theories: 1. tension built up during conflict is released by the performance of irrelevant behaviors 2. conflicting motivational tendencies cancel each other out and allow a lower level of motivational system to be briefly expressed.
What is the general structure of the Y chromosome and what are its functions?
-contains limited # of genes -some function to balance X-linked functions, and some are involved in spermatogenesis -7 genes are in the pseudoautosomal region
b) mate guarding. why?
-females are spread far appart and rarely receptive -males guard and wait for female to be receptive to prohibit other males from mating with the female
healthy mate theory
-females prefer traits that are indicative of male health -adaptive value: females (and offspring) avoid contagious diseases and parasites ex: male satin bowerbirds provide females with multiple signals that are indicators of their health and physiological condition
examples of intentional movements:
-flight signal in the blackbird (ritualized in flocking birds to coordinate movement) -courtship signal by wolf spiders (waving sexual organ is a ritualized signal) -male ballon fly's highly ritualized courtship signal (with various degrees of ritualization form presentation of silk-wrapped prey to empty ball)
Zahavi's handicap principle. why does the trait have to be costly?
-if not, cheaters will evolve -it's not good enought to just say you have good genes, you have to prove it. costly traits guarantee honesty -you can only survive with the trait if you have good genes (in other words--the handicap trait costs less, if you have good genes)
Japanese Reces Mackacks mating/courting behavior
-male leads harem of women -when he gets old, females start having secret affairs wiht younger males -he attacks to reassert his authority over cheating female.
direct benefits of mate choice
-males can provide nutrition, parental care, or superior territory to females --> females seek features that are correlated --> selective pressure for female to recognize superior males
3. Resource defense polygyny
-males defend resources that attract females. basic concept of Polygyny Threshold Model: females should choose territory with greatest amount of resources (highest fitness) regardless of monogamy or polygyny.
furr seals mating/courting behavior
-males fight to win harem of females, sometimes die -male must defend his harem of females-->jealous male neighbors ready to attack -males mate with females shortly after they give birth
2. Female defense polygyny
-males fight with other males to monopolize groups of females. e.g., many mammals ex: elephant seals (as in video) ex: bighorn sheep ex: spear-nosed bats defend harem of females -males benefit by having more females on territory, females do not.
Universals of Attractiveness: 3. Parental Traits. Many men and short-term relationships.
-masculine-faced males are thought to make poor parents but have high quality genes, so they may make bad long-term partners but be attractive in the short-term. -Feminine-faced males are seen as better parents and more co-operative, and so we might expect that they would make long-term partners. *so... women may choose caring men for long-term relationships and more dominant men for a quick affair.
Sensory Drive
-model assumes that sender and receiver co-evolve within severe constraints of the environment -constraints select for senders that give only efficient signals and for receivers that respond only to those signals -background noise, transmission properties, and adaptations to predators/prey will shape signal propagation and receiver sensory design -explains why signals take on particular forms, but doesn't explain how signaling got started in the first place
australian wolf spider mating/courting behavior (peacock spider)
-must "dance for his life" to win female and avoid being eaten by her -after mating, she skills him anyway. his body will be perfect to nourish her eggs.
1. scramble competition polygyny. give example.
-occurs when males skip territoriality/combat and instead try to outrace their rivals to receptive females. ex: horseshoe crabs and salamanders have explosive breeding assemblages. -with mating just a few nights each year... dominant males obtain disproportionate number of mates.
Social learning
-wild white-crowned sparrows occasionally sing other species song -there must be something in addition to acoustical experience that influences song learning process
male pufferfish courting behavior
-works 24hrs/day for 1 week so current doens't destory his sand creation -makes elegant designs in sand by pushing sand around with finds and moving shells -mathematically complex -all to get female to notice him -center of sand creation arena becomes bed for burring eggs
Explosive breeding assemblage in palolo worms
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Explosive breeding assemblage in red crabs
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Extra-pair copulations in indigo buntings (Westneat)
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Extra-pair copulations in superb fairy wrens (Mulder)
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Female defense polygyny in epsilon wasps
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Female defense polygyny in sea lions
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Genetic diversity hypothesis in bluethroats (Fossøy)
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Good genes hypothesis in splendid fairy-wren (Webster)
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Lek polygyny in hammerhead bats (Bradbury)
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Mate-assistance hypothesis in California mice
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Mate-assistance hypothesis in snow bunting
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Material benefits hypothesis in red-winged blackbirds (Gray)
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Monogamy in oldfield mice
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Monogamy in titis
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Polyandry in tamarins and marmosets
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Polyandry in wattled jacana
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Polygynandry in dunnocks
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female preference hypothesis (for leks)
...The female preference hypothesis predicts that males form leks because female like to visit large clusters of males consisting of a variety of potential mates from which she can quickly and safely compare the quality of her mating choices. Rather than accessing them one by one.
what has been discovered about Y chromosome degeneration using neo-Y chromosomes from drosophila?
1) Y chromosome lost 1/3 of its genes, became partially heterochromatic, and had numerous transposons 2) Y chromosome had 15 coding genes mostly containing heterochromatin 3) Y chromosomes mostly involved in spermatogenesis 4) males lacking the Y chromosome (i.e. XO) were superficially normal
How does stopping recombination of sex chromosomes affect degeneration of the y chromosome?
1) cannot repair itself 2) accumulates parasitic DNA i.e. transposons 3) majority of Y becomes repetitive sequence (heterochromatin)
Proximate (general)
1) differences in gene-environment interactions 2) hormonal differences 3) differences in song system construction 4) differences in song system operation 5) song differences among individuals (species, sex, dialect/repertoire)
Even through degeneration of Y chromosomes is common, why is it unlikely that this will result in the demise of men?
1) many species can live without a Y chromosome, and many different sex determining systems exist 2) palindromic DNA sequences on Y chromosomes may allow for DNA repair
How was the Trivers-willard hypothesis proposed in poor vs. rich households?
1) more male offspring/yr in rich households, but not in poor households 2) higher male ratio in rich households 3) lower male survival in poor households (but not in rich households) 4) higher overall male weight in rich households, but lower initial male weight in poor households (potentially due to less resource availability)
What is the purpose of stopping recombination at the sex determining locus?
1) no mixing between male and female genes 2) no linkage or co-transmission of male and female genes 3) provides the chance to optimize either male or female function by attracting sex-specific genes
what are the 3 assumptions that the Trivers-Willard hypothesis relies on?
1) parental condition translates into offspring quality 2) offspring quality translates into offspring breeding success 3) males benefit more from being higher quality based on Bateman's principles (higher variance in fitness)
How does the inactivation of the X chromosome occur in lyonization?
1) paternal X is imprinted and shut off during early embryogenesis (turned on again later) 2) one X copy is "lyonized": condensed into heterochromatin (non-recombining) which produces potential for genetic mosaicism
Provide evidence for how bias of showy males in some species may stem from differences in sex chromosomes, specifically species with ZZ/ZW or ZZ/ZO systems
1) rare alleles encoding male ornaments or female preference for ornaments are better protected against random loss in male heterogametic systems (ZZ/ZW or ZZ/ZO systems) 2) male secondary sexual characteristics are better developed in diploid species with male homogamety over haplodiploid or male heterogametic species
Why does the evolution of heterogametic sex chromosomes result in a vicious cycle between males and females?
1) sexually antagonistic genes result in evolution of heterogametic sex chromosomes, which in turn create an accumulation of sexually antagonistic genes on the X chromosome 2) in females, dominant alleles can become common even if they harm males because females have twice the number of X chromosomes 3) in males, recessive alleles can also become common even if they harm females, because male X-linked genes are expressed in a hemizygous state
what is a Barr body and what types of species contain Barr bodies?
1) the inactive X chromosome in a female somatic cell, rendered inactive by lyonization, 2) in species where sex is determined by the presence of the Y (including humans) or W chromosome rather than the diploidy of the X or Z
Ultimate (general)
1)differences in reproductive success=natural selection 2) genes transmitted to the next generation 3) differences in gene-environment interactions in individuals
6 cost of sexual reproduction.
1. Break up favorable gene combinations. 2. Sex halves relatedness between parent and offspring. 3. Search for mates and Courtship requires time and energy. 4. Exposure to predators when searching for mates. 5. Parasite infection and sexually-transmitted diseases
Combining beneficial mutations and generating novel genotypes
1. Brings together separate beneficial mutations in a single individual. 2. Occurs faster than arising spontaneously in the same genome. 3. Allows for quicker adaptation to changing environments.
What behavioral life stages do individual bees progress through?
1. Cleaning cells 2. Feed larvae 3. Feed nestmates 4. Pack pollen 5. Forage
Why isn't sexual reproduction replaced by asexual more often? (Benefits of sexual reproduction)
1. Combining beneficial mutations and generating novel genotypes. 2. Clearance of deleterious mutations. 3. Reduction of sibling competition. 4. Fighting parasitic infection & the Red Queen Effect.
Behavioral genomics
1. Conduct trials to elicit mating behavior 2. Extract brains, look at expression (mRNA) 3. Identify genes differentially expressed between different social situations 4. Look for genes only expressed in certain social situations 5. Pick genes relevant to your behavior 6. qPCR to quantify expression
Caveats (problems for scientists)
1. Confounding variables: (long neck giraffes for predator vigilance or foraging) 2. Correlation is not causation: (everyone who wore a red hat was struck by lighting. so wearing read hats draws lighting???) 3.Retroduciton: if the hypotheses were correct it would explain the phenomenon 4. Just-so stories: panglossian adaptions 5. Simposon's paradox: unobserved heterogeneity can influence conclusions
Criteria for Sensory Bias/Exploitation
1. Species has trait and preference 2. Trait absent or primitive in ancestors 3. Preference originated before appearance of trait 4. Bias in perception or cognitive system that predicts bias
Hypotheses for sex evolution
1. Diverse offspring: due to recombination results from independent segregation and from crossing over of meiosis, leads to disease resistance 2.Repair hypotheses: asexual reproduction produces some negative mutations occur through genetic drift sexual reproduction can decrease negative mutations 3.Shifting benefits hypothesis:some times sex pays, sometimes it does not (aphids switch back and fourth from sexual to asexual generations depending on seasons)
Tradeoffs in life history
1. Effort allocated toward reproduction reduces effort that can be allocated to the individual's own growth and survivorship 2. Effort allocated toward current offspring reduces the effort that can be allocated toward future offspring
Exceptions to lower male investment rule
1. External fertilizers (females leave so males must stay if they want offspring to survive. ex. penguin) 2. Some birds and mammals IF=internal fertilization EF=external fertilization
What is the logic behind natural selection?
1. Individuals in a species vary 2. These variations have differential reproductive success 3. Kids tend to look like their parents because traits are heritable If all these are true, traits with greater reproductive success will occur in a greater proportion of the population in successive generations.
What type of anti-cuckoo adaptations to cuckoo hosts evolve, how have cuckoos evolved to counter these?
1. Initial defense -Mod adult cuckoos/abandon nest -Selects for sneaky cuckoos 2. Next line of defense -Reject foreign eggs -Selects for eggs that resemble host (better egg mimicry) 3. Reject cuckoo nestling -Cuckoo chick ability to mimic brood sound
In relation to hatch asynchrony, parent offspring conflict theory predicts that (2):
1. Later hatching offspring should suffer higher mortality as a result of reduced care 2. Resource availability should affect survivorship
How do males invest differently into gametes than females?
1. Less investment by males. 2. Relatively small inexpensive in sperm. 3. Time and energy pursuing more chances to mate. 4. Paternity is uncertain.
4 strategies males use to prevent subsequent matings.
1. Mate guarding to chase off rival males. 2. Chemicals in semen kill sperm of other males so female unreceptive to more mating. 3. Giant sperm that fill up entire female reproductive tract. 4. Copulatory plugs: inserting mucus into female reproductive tract.
what are the two general mating categories?
1. Monogamy: -members of a given sex have just 1 mate during a breeding season 2. Polygamy: -members of a given sex have >1 mate during a breeding season.. sub categories of polygamy: polyandry polygyny
What are some of the major functions of complex, multimodal signals?
1. More signal content 2. More effective transmission 3. More effective perception
Testing Hypotheses
1. Observation: evidence that eliminates alternatives 2. Comparative Method: phylogenetically independent contrasts homology convergence 3.Experiments: reduce effect of confounding variables 4.Rejecting hypotheses: is useful but cannot be the only strategy
Developing Hypotheses
1. Observe: patterns, anomalies, paradoxes 2. Generate: multiple alternative hypotheses 3. Create mathematical of graphical models -make explicit quantitative predictions
Examples of mate choice without material benefits
1. Peacocks (more eye spots = more mating success) 2. Long-tailed widowbird study - shortened or lengthened tails, assigned to different areas and measured # nests with eggs -->elongated tails as supernormal stimulus!
What type of antipredator behavior can be employed after predators attack?
1. Physical defenses 2. Chemical defenses (Bombardier beetle) 3. Deceive/Startle, Confuse (Moth eye spots, Killdeer wounded display, brittlestar autotomy) 4. Alarm calls
How do females invest differently into gametes than males?
1. Produce large, yolk-rich gamete. Reproductive success rarely,limited by sperm. 2. Post-fertilization investment: Parental care. 3. Maternity is certain.
Why don't receivers ignore deceitful signals?
1. Receiver has not caught up in coevolutionary arms race 2. Receiver still benefits on average by responding to signal
Ritualization involves one or more of the following four changes in a cue:
1. Simplification- or reduction in the number of components 2. Exaggeration-of the remaining components 3. Repetition-of the signal 4. Stereotypy-or reduction in the variance of signal from doing repeated rendition of the signal
Why do some researchers see a link between language and consciousness?
Development of language coincides with reflective consciousness. Gives a space for thinking about thinking.
Best Evidence for Sensory Exploitation (2 cases)
1. Tungara Frogs (physalaemus pustulosus) -female frogs prefer male calls (chucks) with more low-frequency energy -female's ear exhibits maximum sensitivity at a frequency slightly lower than the average male's call (Ryan et al 1990) -Ryan argues that the preference was present before signal -Males evolve signal to "exploit" response
Case studies of sensory bias/exploitation
1. Water Mite (Neumania papillator) -male bug lifts his legs to elicit a response from the female (that is un sex related) but it lunges her forward and he droops his sperm on her eggs when she lunges forward. *See textbook for more info! 2. Swordtail fish--female preference evolved prior to male swordtails -classic example by Alexandra Basolo: Greed swordtails-males have tails Platyfish relatives-males lack tales Asked: is there preference fro long tails by female swordtails? Methods: Male had transparent tail attached and male had natural color tail attached. YES... females spent more time near large-tial males and *criterion 1 is met Did the preference arise before appearance of trait? Tested preference on Platytails to answer this question. YES... females prefer males with a visible sword! *criterion 2 and 3 met. BUT... did the sword trait arise before the platyfish? Basolo retested her hypothesis with the Priapella fish (which is even further down the phylogeny where the tail is absent in all versions) and... YES females preferred sworded male. *criteria 2 and 3 met for reals! However, criterion 4... bias in perception or cognitive system that predicts bias? This is still unknown. Speculation why females might prefer swords in Priapella. Criterion 4 not yet met.
conflict between reproductive strategies of males and females
1. females produce relatively few large gametes vs males with many small gametes 2. males can mate frequently with little cost; female fitness correlated with male mate 3. females are often limiting resources for males --> male skewed sex ratio often exists --> variation in mating success among males is greater than females ------> this is a way to measure strength of sexual selection
bateman's principle
1. females should be choosier sex because eggs are expensive and female's reproductive success is limited compared to males 2. greater variance in reproductive success of males secondary epigamatic sexual characteristics are important in attracting mates
Why Sex? Costs and benefits
1. genes of sexual organisms "diluted" by 50% compared to Parthenogen (reproduction without fertilization ex. meiosis) 2. sex did not evolve for reproduction
six theories for why females show preferences for males that provide no parental care or material benefit
1. healthy mate 2. good genes 3. handicap principle 4. runaway selection 5. sensory exploitation 6. chase away selection
Visual signals evolve from three types of sender sources:
1. intentional movements 2. motivational conflict 3. autonomic processes
same-sex contests
1. male contest --> associated with weaponry (horns, tusks, antlers) --> associated with visual or audio displays (colors, ornaments) 2. directional selection for greater size, weaponry, or display features leads to "arms race" --> leads to evolution of more extreme traits 3. evolution of traits to limit mating opportunities for other males --> defense of mating territories --> prohibiting future mating events (copulatory plugs) 4. sperm competition --> evolution of morphologies to remove sperm from previous matings --> evolution of larger testes ( to produce sperm in greater numbers) --> diversity of sperm morphology driven by sperm competition --> females can dominate sperm precedence (fertilization of eggs by only one mate despite multiple mating events)
Evolutionary steps for females to be emancipated from care
1. males care for the eggs 2. females become able to lay more eggs than a male can care for 3.females compete to lay two or more clutches in sequence for different males
male reproductive success most often assessed by:
1. number of mates 2. fecundity of mates 3. proportion of mate's eggs fertilized
list the four types of polygyny
1. scramble competition polygyny 2. female defense polygyny 3. resource defense polygyny 4. lek polygyny
indirect benefits of mate choice
1. sensory bias-inherent tendency to react to exaggerated stimuli (not normal) --> female preference evolves first and then males select for that exaggerated trait --> sensory bias can initiate a process of sexual selection Models: - Runaway sexual selection - Good gene models 2. sex role reversals can occur where females compete for males -males often care for offspring with sex role reversals 3. in species with both parents providing parental care, both sexes may select mates -results in sexually monomorphic ornaments or displays
sexual conflict
1.conflict of evolutionary interests between males and females 2.optimal for males to mate repeatedly with previously mated females 3.optimal for females is to mate only once (or a few times) --> Chase away selection --> males may inflict harm on mates -----> forced copulation -----> damage to female organs/reproductive apparatus -----> toxins that limit lifespan of females (seminal toxicity) 4. Sexual conflict of gametes -sperm evolve strategies to penetrate eggs while eggs evolve features to limit polyspermy -sperm morphology has evolved rapidly due to competition from other sperm and antagonistic coevolution between sperm and female reproductive tract
Pheremones have a low volatility and diffusibility when used to communicate alarm. True or False.
False
Monogamy in birds
90% of birds show social monogamy within a breeding season; DNA tests show that social monogamy is not the same as genetic monogamy; common in birds because males can be effective caregivers (incubate eggs, feed offspring, protect eggs and offspring); males can substantially increase their own reproductive success.
Sister sister relatedness
75%
eusociality
A complex social structure in which workers sacrifice most or all of their direct reproduction to help rear the queen's offspring. Common in insects such as ants, bees, wasps, and termites.
Sexual Dimorphism
A difference in form between males and females of a species, including color, body size, and the presence or absence of structures used in courtship displays (elaborate tail plumes, ornaments, pigmented skin patches) or in contests (antlers, tusks, spurs, horns).
Sexual dimorphism:
A difference in form between males and females of a species. Including color, structures for courtship display or contest.
intrasexual selection
A direct competition among individuals of one sex (usually the males in vertebrates) for mates of the opposite sex.
sexual selection
A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.
Female distribution theory
A general explanation for the diversity in mating systems that arises because females of different species are spatially distributed in different ways (due to distribution of resources), which affects the fitness gains derived from different male mating tactics -Female reproductive success is tied to resources more than the number of mates. -Male reproductive success is tied more to number of mates than to resources. -Females should track the distribution of resources and males should track the distribution of mates. -If females are widely dispersed, males should mate with one female -If females occur in defensible clusters because resources are clumped, males will compete for those clusters
Central Pattern Generator
A group of cells in the CNS that create signals that result in a functional behavioral response
hotspot (as it refers to leks)
A location whose properties attract sexually receptive females to the male able to hold the site against rival males. Hotspot hypothesis: a tentative explanation for why males cluster their display territories in a lek. The clustering is said to occur because males compete to display near a place that tends to attract females.
Advantages of ESS
A major advantage of the ESS is that it can be resolved from phenotypic considerations alone without having to account explicitly for the (often unknown) underlying genetic detail.
If male white-crowned sparrows are reared in the laboratory under controlled conditions, what kind of male will produce a species-specific song as an adult?
A male reared in isolation and exposed to recordings of his species-specific song before 2 months of age and hears the songs of conspecifics during his first breeding season, or a male reared in isolation and exposed to recordings of his species-specific song before 2 months of age and then deafened after his song has crystallized.
Extra-pair copulations
A mating by a male or female with an individual other than their primary partner in a seemingly monogamous species
Explosive breeding assemblage
A mating system in which a large proportion of the adult female population becomes receptive on one or a very few days of the year
Monogamy
A mating system in which a male and female mate only with one another during a given breeding season; rare in mammals (~3% of species) because female investment is so extensive that males benefit by finding more mates
Female defense polygyny
A mating system in which males aggressively guard females who are found in spatial clusters, obtaining sole reproductive access to such "harems" of females
Polygyny
A mating system where males mate (or attempt to mate) with multiple females.
Polyandry
A mating system wherein females mate with more than one male per breeding season
Polygyny
A mating system wherein males mate with more than one female per breeding season
Polygynandry
A mating system wherein several males form bonds with several females simultaneously
pleiotropy
A single gene having multiple effects on an individuals phenotype
evolutionarily stable strategy (ESS)
A strategy that cannot be replaced by an alternative strategy. i.e. "the resident always wins.", A behavioral strategy that results in the most offspring, which individuals in a population must adopt because most others have adoped it. The group's strategy selection inherently reduces the effectiveness of any alternative strategy, unlessconditions change.
adaptation
A trait with a better ratio of fitness benefit to fitness cost. 1. A trait that has been spread in the past and maintained 2. A trait that is currently spreading relative to alternative traits b/c of natural selection.
Promiscuous mating systems
A type of mating system in which both polyandry and polygyny are occurring
Degrees of ritualization in the courtship displays of Pheasants form a food-advertising source
A) males give food calls and feed mates in Bobwhite quail. B) and C) Chickens and Ring-Necked Pheasants are intermediates D) male Impeyan pheasants pecks ground, holds head still and then makes low bow and tail fan. F) Peacock courtship display contains low bow and fail fan with bill pointed to ground, but no food or pecking. -->derived form of courtship feeding
How does the noctuid moth's simple ear allow it to detect and evade bats? Two receptors A1 and A2
A1- sensitivity to low intensity sounds, more firing with greater sound intensity, only responds to pulsed ultrasound · A2- Only responds to high intensity sounds- Terminal buz
How does the noctuid moth's simple ear allow it to detect and evade bats?
A1: location and movement information, when A1 fires in one ear sooner the moth will fly to equalize the signal in both ears A2: dive (this is when bat is to close to fly away)
Signal Honesty Q: why doesn't natural selection favor animals that 'cheat'? give an example.
A: because natural selection often acts to enforce honesty in signals thus, selection favors message that conveys accurate (honest) information. good example=deer roar -only male red deer (stags) in top condition can roar for extended period of time. Signal is condition-dependent
Sensory neurons
Afferent Sensory---> CNS
foraging
All behaviors related to obtaining resources (resources are things that increase fitness). Big three categories of resources are food, sex, and shelter.
How does jumping courtship serve as an example of sensory exploitation?
All females prefer exploiting males. Males know what females like and they give it to them. SR females prefer AT males, AT females show no preference
What do females who choose males with attractive traits pass on to their offspring?
Alleles influencing the expression of both the preference and the trait. The resulting genetic correlation between preference and trait can lead to an escalating positive feedback cycle of coevolution of stronger preferences and larger display traits.
Circumvention
Allow herbivore to bypass defense. Like vein-cutting on milkweed.
How is a genomic approach useful for identifying the genetic basis for these behavioral stages?
Allows us to tell what genes relate to what traits, so we can compare other species microarrays and understand the genetic factors leading to other behavioral traits
Game Theory
An evolutionary approach to study adaptive value in which the payoffs to individuals associated with one behavioral tactic are dependent on what the other members in the group are doing
Optimality Theory
An evolutionary theory based on the assumption that the attributes of organisms are optimal (that is, better than others in terms of the ratio of fitness benefits to fitness costs)
Reciprocal Altruism
An exchange of fitness benefits that are separated in time. Reciprocal altruists help those who have either helped them in the past or are likely to help them in the future. Reciprocal altruism is also used as an explanation for the helpful and cooperative behavior commonly observed among unrelated humans.
A cost commonly associated with group living is ______.
An increased risk of predation, interference with foraging, increased exposure to diseases and parasites, and increased competition for mates.
Simultaneous polygyny
An individual maintains numerous mating partners in the same general time frame
Fixed action patterns
An innate, highly-stereotyped response activated by a simple, well-defined stimulus
cost-benefit approach
Analyzes phenotypes in terms of fitness benefits and fitness costs. An adaptation occurs when benefits outweigh costs.
conditional migration
Animal can migrate or remain sedentary-- choice is made based on social factors. i.e. European blackbird
Cost-benefit Analysis
Animals appear to weigh the costs and benefits of responding to a particular situation in various ways. Costs and benefits are measured in terms of their impact on fitness.
How is learning ability related to the natural environment of an animal (like a lab rat or a vampire bat)
Animals are only able to learn behaviors that would be natural to them or beneficial for their survival evolutionary. Rats: can learn to avoid water after being made nauseous but not to associate a bell with the nauseous feeling because sound and nausea don't naturally occur to them
Why is the reproductive success of individuals in different quality habitats generally equal if they conform to an ideal free distribution?
Animals distribute themselves in a way to maximize their reproductive success. "High quality" habitats are only good at certain population densities
ideal free distribution
Animals will distribute themselves spatially to maximize reproductive success.
leads to biases in the OSR.
Anisogamy leads to differential investment by males and females, which leads to biases in the OSR. Biased OSRs lead to sexual selection.
Regarding circadian rhythms: a mammal maintained in complete darkness and at a constant temperature will become arrhythmic. True or False.
False
How are ambivalent or displacement acts beneficial? give an example
Answer= if they result in useful information for sender and receiver example: territorial dispute -at a point near boundary ambivalent or displacement acts can appear (aggressive displays are strongest at center of territory while fear is expressed outside territory) -the performance of ambivalent or displacement behaviors are good indicators of how far the resident is prepared to go in defense of his or her territory or they could serve to de-escalate a conflict.
What can sexual conflict lead to?
Antagonistic coevolution and arms races between males and females. Mutations advancing the reproductive interests of males select for countermeasures in the females, and vice versa.
Antipredatory behaviors Identify as prey, decide to attack
Aposematism Mimicry Unprofitability advertisement
Females often choose males based on what?
Appearance or details of their courtship behavior.
Lek polygyny
Areas in which groups of males set up and defend small, temporary territorial patches and in which they display to females, specifically to attract females to mate with them; called lekking or arena mating; leks contain no resources; females select among the males, copulate, and leave with no care provided from males
Model for the evolution of Anisogamy
Arose from isogamy. Probably an ancestral marine organism that sheds gametes into water. Proto-sperm & proto-egg produced. Most zygotes come from small gametes (proto-sperm) fusing with other small gametes due to the large numbers produced. But if proto-sperm fuse with large gametes (proto-eggs) they have higher survival, favored by selection. (Large fusing with large best but rare) Disruptive selection.
How do territory sizes shift as their quality changes?
As quality increases, territory becomes smaller. As quality decreases territory becomes larger (need to expand to find resources needed to survive)
Regarding genetic influences on behavior: a single gene usually codes for complex behavior.
False
How do studies of Darwin's finches show natural selection in action?
As the environment changed (drought) so did the beak shapes. Birds had different beaks that were best suited to their unique environment.
As number of female sage grouse mating per day increases, the number of hens that chose a previously-mated male increases (mate-choice copying)
As you selected strongly for something, variation decreases, because you are only letting a small subset of the population reproduce
Cost and benefits of being an asexually reproducing female:
Asexual female produce twice that of sexual females. Only daughters are produced. Asexual genotypes should increase in frequency.
Twofold cost of sex:
Asexual lineages multiply faster than sexual lineages because all progeny are capable of reproducing. In sexual lineages, half the offspring (males) cannot reproduce, thus halving the rate of replication.
How does the experiment by Seed et al. experimental design allow them to discriminate associative learning from an understanding of causal mechanism?
Associative learning: low-level cognition Understanding causal mechanism: high-level cognition One bird was able to transfer knowledge to a tasks that required the opposite response (causal mechanism)
What types of assumptions go into the creation of an optimal foraging model?
Assumes a certain currency (energy or time) is being optimized
Asymmetric game vs Zero-sum game
Asymmetric game: the two players have different strategy options Zero-sum game: whatever one player gains, the other loses -each player wants to do whats best, whatever the other does -goal: avoiding the worst possible case is a high priority
Honestly and badges of status (social status signals)
Badge of status model (Moller 1987) -honesty is insured if large badges are challenged and there is a cost of being aggressive (testosterone) -size of patch is strongly correlated with dominance rank in birds -males with experimentally enlarged patches were attacked more often -large-badged males exhibited higher autumn mortality (the cost of aggressiveness; imunocompetence)
Why is the relative frequency of models and mimics different under Batesian and Mullerian mimicry?
Batesian: palatable mimic imitates and unpalatable model (many more mimics than models) Mullerian: two unpalatable species resemble each other (same amount of models and mimics because they are one in the same)
Why is anisogamy an important driver of behavior?
Because it constitutes a difference between the sexes in their relative investment in offspring. Because of this, males and females maximize their reproductive success in distinct ways.
Why do mating systems evolve?
Because of the benefits and costs they confer on males and females. Who mates with whom can depend on the opportunities that arise through both inter- and intrasexual selection. In some species, a combination of systems may be at play.
Why may sexual reproduction have evolved?
Because sex creates new genetic variation within populations by mixing parental alleles into novel offspring genotypes while at the same time enabling the purging of deleterious alleles.
Why will costly signals or display traits be the most reliable?
Because they are difficult or impossible for those of poor genetic quality to bluff.
How does our visual filtering and color vision differ from that of honeybees?
Bees and humans are trichromatic. Humans cannot see UV. Bees cannot see red. Birds have tetrachromatic visual systems.
Male perspective
Benefits: More offspring raised by another male. Costs: a) Time spent searching for another mate. b) Risk of unguarded female mating with another male. -Males tend to guard their female closely during her fertile period but seek new partners afterward.
How does sex differentiation differ between birds and mammals?
Birds -Ovary organizing -Males homogametic -Absence of ovaries = male secondary characteristics Mammals -Testes organizing -Females homogametic -Absence of testes = female secondary characteristics
What is the explanation for why birds have song dialects at all four levels of analysis?
Birds have evolved to have different song dialects in order to communicate with neighbors (friend or foe), also to find and "impress" females for mating and ensuring that their genes will get passed on to the next generation. This has to do with the proximate analysis where an individual's mechanisms (brain anatomy) and its development of behavior (learning) during its life allow them to learn different songs depending on the situation that will aid them. This will add to the populations' function to increase fitness (reproduction) and increase survival within the population/species which explains why certain traits like song dialects have been evolved due to descent with modification.
2) Blending
Blending of antithetical intentional movements into an intermediate form.
combined strategies
Both male and female have multiple mates in one season; the female is polyandrous and the male is polygynous (or it can be said that both are promiscuous).
Promiscuity
Both males and females mate with many partners and no pair bonds are formed
Hamilton's Rule
Br > C. States that altruistic behavior is most likely when three conditions are met. B = fitness benefit to the beneficiary (avg. # of extra offspring beneficiary will have), C = fitness cost to the altruist (avg. # of fewer offspring altruist will have) 1) The fitness benefits are high for the recipient 2) The altruist and the recipient are close relatives 3) The fitness cost to the altruist are low
What is the logic behind clock-shifting experiments with pigeons?
By shifting the clock on the pigeons they will not know what direction the sun is facing therefore their compass will be shifted and they can be confused as to which direction to go.
Why is the initial evolution of aposematism problematic?
Cannot have RS if you die. Likely evolved from non-deadly attacks
What is the neurological mechanism in birds underlying perception of photoperiod?
Change in sensitivity to light (the cycle resets every morning at dawn, then insensitive for 16 hours). Experimentally, even if days are made shorter, if daylight occurs at critical period testes will grow.
Depending on the species, females may select males based on what?
Characteristics that benefit her directly (such as nutrients, nest sites, protection, parental care) or indirectly (e.g., high genetic quality transmitted to her offspring).
How is the bombardier beetle able to spray noxious substances on its predators?
Chemical reactants stored in an internal chamber. Small chamber with enzymes which catalyze reaction. Accuracy maintained by valve.
What do traits that strike the females' fancy allow females to d o, even though they may originally be arbitrary?
Choose males based on characteristics that reliably distinguish the highest-quality, healthiest individuals from the rest of the lot.
camouflage
Color or shape that helps to hide an animal from visual predators when on its normal substrate.
does the previous discussion of sexual selection, mating systems and social behavior apply to humans??
Comparisons are difficult because biology does not justify cultural and individual differences and ideological belief systems.
Define competition and list and discuss its fundamental features. Would interspecific or intraspecific competition be expected to have the greatest impact on a particular individual in a population? Why?
Competition: #2 individuals using the same resources, resource reduction by 1, fitness is reduced. Features: Use of common resources, limiting resource, asymmetric (Winner is competitive dominant, lose is competitive subordinant), density dependent. Intraspecific has greatest impact on individual in a population because of direct competition.
competitive dominant/subordinate
Competitive: wins the resources in competition (most or all). Can ensure reproduction to the next generation. Subordinate: loses the resources in competition (most or all). Could lead to death.
How might animal consciousness be analogous to an eye?
Consciousness takes in all information, just like an eye
contest/ scramble competition
Contest: allocates resources to a winner or a group of winners in an intraspecific competition. Scramble competition: a free-for-all scramble for limited resources among individuals of the same species (intraspecific)
Resource defense polygyny
Control of resources valuable to females (spanning substrate, nesting cavity, food resources, even protection from harassment by other males ex. male yellow black birds very good at attracting females
Eavesdropping/Exploitation
Cost the sender and benefits the receiver
Which of the following is NOT likely to be a result of a skewed operational sex ratio? A. Male bighorn sheep butting heads. B. The extended head of a stalk-eyed fly. C. Female seahorses fighting over egg space in a male's pouch. D. A goby fish cannibalizing some of its own eggs. E. All of these result from a skewed OSR. F. None of these are the result of a skewed OSR.
D. A goby fish cannibalizing some of its own eggs.
The Descent of Man and Selection in Relation to sex
Darwin's book about his hypothesis as to how natural could favor trait such as bright colors, horns, behavioral displays. (1871)
Homing
Dead reckoning or path integration. Movements to fixed goal or known location. Requires compass and odometer sense.
Why does dead reckoning require a compass and an odomet
Dead reckoning requires that you know how far/ how many steps need to go and what direction since not using any other cues from the environment
cost-benefit analysis
Decisions or analyses that weigh the fitness costs and benefits of a particular action.
Why do pigeons in different areas use different cues for map and compass information?
Depends on the reliability of these cues in the environment they grew up
payoff asymmetry
Difference between what an established territory holder has to lose and what a challenger has to gain in a territorial contest.
Twin studies (genetic variability underlying trait variability)
Different characters have different correlation. Identical twins raised in different environments, have same genome environment is all that differed.
Leads to biases in Operational Sex Ratio (OSR).
Different strategies lead to sex differences in reproductive rate. Leads to sexual selections.
Why do females mate voluntarily with more than one male?
Different systems might be explained by different things. Doesn't necessarily have one unitary hypothesis to explain everything Genetic benefits polyandry 1. Fertility insurance hypothesis: Mating with several males reduces the risk that some of the eggs will remain unfertilized due to mating with a partially or completely infertile male 2. Good genes hypothesis: trading-up, trying to get better genes 3. Genetic compatibility hypothesis: Mating with several males increases the genetic variety of the sperm available to the female, increasing the chance that some will be genetically compatible with her eggs Material benefits polyandry 1. More resources hypothesis: More mates mean more resources or parental care received from the sexual partners of a female 2. Better protection hypothesis: More mates mean more time with protectors who will keep other males from sexually harassing a female 3. Infanticide reduction hypothesis: males kill young so that female would be ready to give birth to their offspring--more mates mean greater confusion about paternity of a female's offspring and thus less likelihood of losing offspring to infanticidal males
Sexual Selection
Differential reproductive success resulting from the competition for fertilization, which can occur through competition among individuals of the same sex (intrasexual selection) or through attraction to the opposite sex (intersexual selection).
On April mornings, you step outside your front door and notice the singing of a male robin. At that time you also observe that the female of the pair is building a nest in a nearby tree. A month later you observe the pair feeding their nestlings. What question could you ask about the cause of the birds' behavior?
Do robins that begin nesting in April raise more offspring than they would raise if they delayed nesting until June, and if so why?
All of these are strategies used by male insects to increase the likelihood that their sperm will fertilize a female's eggs, except: A. Guard females after mating. B. Physically remove sperm by inflating the penis or using a penile flagellum. C. Inject chemicals that induce females to avoid re-mating. D. Tear the female reproductive tract. E. None of the above. Males do all of them.
E. None of the above. Males do all of them.
Hatch Asyncrhony and Brood Reduction in Blackbirds (Forbes et al. 2002) Hypothesis
Early-hatching offspring are larger than and competitively dominant to their siblings.
What types of animal interactions involving information transfer qualify as communication, and what types don't?
Eavesdropping is not communication. Batesian/aggressive = deceit Mullerian = honest
How is heritability measured and why is it difficult to generalize heritability values?
Equation h2= VG/(VG+VE) Challenges: behaviors are too complex to measure actual genetic contribution, parent/offspring regression (continuous traits). Many genes may be responsible, each with small effects. Lots of variability due to environmental effects. Heritability is for specific environment ONLY.
In general how do common garden experiments, hybridization studies, twin studies, mutations studies, relatedness studies, and artificial selection studies establish that there is genetic variability underlying variability in a trait of interest?
Even in different environments some traits still appear so this shows that there is some underlying genetic factor acting on these traits.
When long-day adult hamsters made arrhythmic by destruction of their suprachiastmatic nuclei (SCNO) cubsequently received SCN tissue from short-day fetuses, their circadian rhythms were restored and the restored rhythms had long-day lengths. True or False.
False
Why do pigeons in different areas use different cues for map and compass information?
Everywhere doesn't always have the same signals. Magnetic field could be off or sun blocked by clouds most days. Need different ways of setting direction depending on the environment where they were raised.
What is the relationship between evolution and natural selection
Evolution = descent with modification (gene frequency change) Natural selection = most powerful mechanism to produce cumulative change and adaptation (match to environment) Change can also happen via random mechanisms Genetic drift: increase or decrease in genes by chance, especially in small populations Involves differential passing down between generations... but not as a consequence of parent individual's traits Results in change, but not adaptation
adaptationist approach
Examines the evolutionary foundation of a behavior-- is it an adaptive product of natural selection?
Chase-away selection theory
Example of sexual conflict (sensory exploitation) - Male trait provides no benefit to female --> females become less sensitive to male trait ----> in response, males ENHANCE trait ------> leads to costly exaggerated male ornaments of no valie bedbugs
What type of mating system do midshipman fish have?
External fertilization, organizational Type 1: larger, sing, defend/care Type 2: small, cannot sing, sneakers
Animals are expected to defend feeding territories when food is widely distributed. True or False.
False
Fixed action patterns are induced by complex, species-specific stimuli. True or False.
False
Helpers at the nest maximize their individual fitness, but reduce their inclusive fitness. True or False.
False
Imprinting is an example of a fixed action pattern. True or False.
False
Once a male white-crowned sparrow has learned his song, testosterone is unnecessary for the expression of song. True or False.
False
How does landmark navigation work
Finding way based on landmarks and not on compass or any directional cues
Polygyny Threshold Model (Orians 1969)
Fitness of 2nd female sharing a male on high quality territory is equal to the fitness of female who nest monogamously on low quality territory -this quality creates a decision threshold (if there was an option to be a single female on an intermediate quality territory, they would do that) -Graph illustrates fitness to 2nd female on the high quality territory. The distance between curves is the fitness cost of being a 2nd female. She should be polygynous whenever the fitness being a 2nd female on high quality territory > fitness of being only female on lower quality territory.
Direct benefits of being choosy.
Food, Nest sites, Protection, Help with raising young. Nuptial gifts, cannibalism.
Red-queen effect:
For co-evolving populations to maintain relative fitness, each population must constantly adapt to the other. Biological arms races, such as those of parasites and hosts.
Paternity Uncertainty and Parental Care in Boobies Conclusion
For experimental males, certainty of paternity was low for the first egg laid, but was higher for subsequently laid eggs because the pair copulates during egg laying.
Can you describe how sexual reproduction occurs in redback spiders?
Male inserts his palp into the female spermathecae. Then somersaults so he is over the females mouth, and he is eaten in the process.
Karl von Frisch
Founding father of ethology that focused on honeybess
Nikko Tinbergen
Founding father of ethology that termed levels of analysis and fixed action pattern
Konrad Lorenz
Founding father of ethology who studied instincts, imprinting, and critical period
What factors will cause threshold shifts in the egg discrimination-threshold model?
Frequency of encounters Cost of rejection (shift right) Cost of acceptance (shift left)
Unit of selection
Genes (replicators)
Why is natural selection a population process
Genes are the unit of selection (replicators, genic selection) Level of selection usually individual organisms (interactor) Exceptions Intragenomic conflict--meiotic drive in fruitflies from selfish genetic elements on Y chromosome Eusocial insects
Why do predators and prey in coevolutionary cycles exhibit a geographic mosaic of adaptations and counter-adaptations?
Geographic mosaic is indicative of cost to counter adaptations. Without tradeoffs, an arms race would never occur
How does the organizational cascade differ between type I and type II males
GnRH from the forebrain sends signal to pituitary releases gonadotropins > gonads release steroid hormone > steroid hormone organize sexual morph. It depends on the male's size when cascade happens
Where do golden egg bugs lay their eggs?
Golden egg bug females lay eggs on leaves (no parental care) or on the backs of males (parental care)
Multiple matings are costly at the 'species' level
Graph: Degree of polyandry in species vs. Measure of white blood cells -The more polyandrous species are prepared for disease risk, and have evolved to have more white blood cells -Disease risk from mating with multiple partners
How would an animal behaving in accordance with the optimal GUT model change its behavior in response to changes in the parameters of the model?
Greater distance between patches = increase in GUT Less distance between patches = decrease in GUT
Indeterminate growth
Growth that continues throughout the lifetime
Hatch Asyncrhony and Brood Reduction in Blackbirds (Forbes et al. 2002) Conclusion
Hatchling asynchrony facilitates brood reduction by creating offspring of different sizes and competitive ability.
Renunciation
Herbivore does not include plant as part of diet
Utilization
Herbivore unaffected, utilizes plant's defense for own purposes
What potential costs and benefits might affect the level of testosterone for a given species at a given time?
High T levels can lead to low immune system - lower survivability · Can cause fighting with other males=less parental care - lower fitness · Increase metabolism · Risk of injury or death in courtship fights · Increased sperm production · Increased attractiveness to females · Increased territory size · Increased number of fledglings produced.
Fixed Action Patterns (FAPs)
Highly inflexible, stereotyped behavior patterns, like yawning and sneezing.
The lek paradox
Highly skewed mating success generates an ultimate problem: how are strong female preferences maintained despite strong directional selection? -It's a paradox because variation is present! Possible solutions: -Females in fact mate with more than 1 male and thus maintain genetic variation -Genetic variation is already present and the expected lack of genetic variation is an illusion -can be demonstrated if a selection experiment generates a response to selection -Non-genetic benefits of mating with dominant males (assumes dominance is not heritable) -e.g., may mate with strong males and doesn't get injured and by doing so
fixed action patterns
Highly stereotyped behavior pattern that occurs in a certain invariant way in a certain species. (FAPs)
How does our visual filtering and color vision differ from that of honeybees and birds?
Honeybees do not see red they only see black however they and birds are able to see UV which humans cannot. Humans and bees both have trichromatic vision (Birds are tetrachromatic; UV, blue, green, and red)
What does the Red Queen Effect refer to?
Host immune systems evolve continuously and quickly in an arms race with parasite populations that are also evolving to evade their defenses.
Which of the following research questions does not refer to proximate causes of behavior? How do rhesus macaques find their food? How do pigeons that are experimentally displaced find their way back to their home loft? How does dispersal affect the survival of Belding's ground squirrels? Do mother goats learn the odor of their offspring? How do hummingbirds "know" when it is time to return to their overwintering grounds?
How does dispersal affect the survival of Belding's ground squirrels?
runaway selection (Fisher)
How it works: 1. initially, a correlation between the trait and over fitness (i.e., signals 'good genes'): slightly longer traits initially confer a survival atvantage 2. Female prefer long-tailed males and have offspring that survive better than average. The gene for this trait increases in frequency in the population. 3. Females then have daughters who prefer long-tailed males and sons with long tails -when this preference becomes common, a female with this preference has two-fold advantage: 1) her sons and daughters survive better, 2) her sons are preferred (she has 'sexy sons') 4. A runaway selection process will then begin with this positive feedback system.
Propose one ultimate cause of human mate choice that is similar to that in Anolis lizards.
Humans, like lizards, tend to choose a mate who will increase their fitness. For example, women often prefer men who will be able to help provide for offspring.
Sensory Drive
Hypothesis suggests that the receiver 's characteristics are shaped by the environment and that will affect signal evolution.
Optimal Foraging Theory
Hypothesis: natural selection should favor efficient foragers, those individuals that maximize their energy or nutrient intake per unit of effort., The basis for analyzing behavior as a compromise of feeding costs versus feeding benefits, anticipating that animals will attempt to maximize energy obtained as a function of time and/or energy spent
Refinements of a Receiver. If there is a benefit to receiver response then...
If there is a benefit to receiver response... -perception (sensitivity) is tuned to better detect and discriminate cue/signal -positive feedback may favor new and improved code acquisition -selection may favor specific preferences -response is refined
Predation Risk and Parental Care in Golden Egg Bugs Results
In 10 out of 11 trials, the last bug alive was one without eggs on its back
Brood patch
In birds, a featherless area on the belly that is well vascularized for heat transfer to eggs during incubation
Juvenile hormones
In insects, a class of hormones produced by specialized endocrine glands that influence molting, are associated with reproductive maturation, and are known to vary with levels of parental care provided to offspring
Is foraging behavior inflexible and innate or flexible and learned?
In most animal species, it is flexible and dependent upon learning, but in fruit fly larvae it is mostly inflexible and innate (rovers and sitters).
Which of the following about the field of behaviorism is false? Scientists such as Pavlov and Skinner were researchers in this field, it focused on questions concerning learning, experiments were conducted under laboratory rather than field conditions, model species, such as the albino rat were used in experiments, or in research, relationships among study species were considered.
In research, relationships among study species were considered.
siblicide
In some species intrabrood rivalry can reach the level where one of the offspring will kill another, called
Biparental Care hypotheses
In some species, two parents may be necessary for successful rearing of young.in such a species the cost/risk retaliation from a cuckolded mate may outweigh the potential benefits of extra pair matings
What would you conclude?
In terms of reproductive success, polyandry is the most beneficial However, the more sex you have, the shorter life you will have. -Life expectancy same for female w/polyandry multiple or monogamous multiple so poly better b/c increases survivorship of eggs
Cue
Incidental by-product of message signaling
A biologist once remarked that he'd be willing to lay down his life to save two brothers or eight cousins. Explain what he meant.
Individuals have an r of 1/2 with full siblings and an r of 1/8 with first cousins. If the biologist will lose his life, he needs to save two siblings, or eight first cousins, to keep the "lost copy" of his altruism alleles in the population.
Reduction of sibling competition.
Individuals with similar genotypes require the same resources. Asexual siblings parents have more reproduction competition. More genetic variability under sexual reproduction. Sex creates opportunity for offspring to specialize in different niches, thereby reducing sibling competition.
What is the logic behind natural selection
Individuals within a species vary in their appearance, behavior, etc. Some versions of those traits give individuals greater chance to reproduce Kids tend to look like their parents: many traits are heritable Darwin realized that if 1,2, and 3 are true... -Then: trait will appear in a greater portion of individuals in the next generation... and even more in the next generation...and so on Thus: Characteristics of the individuals within population change over successive generations because of the differential success of individuals with different t
dear enemy effect
Initially, newcomers to a territory must invest lots of energy defending the territory's borders, but as time passes, borders are agreed upon and the cost of defending the territory decreases.
What is intragenomic conflict and why might it sometimes occur
Intragenomic conflict is the struggle for survival among different elements of the genome. In this struggle, manifested in a number of different ways, so-called selfish genetic elements distort the standard rules of inheritance to gain a transmission advantage over other parts of the genome, often at the expense of the host organism itself. It sometimes occurs as a result of viral genome insertions into the host's DNA or a variety of other factors.
Universals of Attractiveness: 2. Look-alikes
It is a widespread belief that partners look alike (e.g., the 1930 portrait by Grant Wood called American Gothic) -In humnas, mating with similar individuals to oneself may have genetic benefits Theissen and Gregg (1980) proposed: mating with similar-looking individuals increases the changes you share genes in common, and that mating with such individuals could be advantageous. *Genetic compatibility hypothesis
Why do cavity-nesting honeybees have more precision in their dance language than open nesters?
It is harder to find a cavity nest than an open nest, needed better communication
Intersexual Selection
Male choice
Which of the following statements about response to sounds in parasitoid flies and the associated graph to the right is TRUE?
Male flies are most sensitive to sounds around 10 kHz
Why is Hamilton's Rule important?
It shows that individuals can pass on their alleles to the next generation not only by having their own offspring, but also by helping close relatives produce more offspring.
Hamilton's rule
It states that altruistic behavior is most likely when three conditions are met: 1) The fitness benefits are high for the recipient, 2) The altruist and recipient are close relatives, and 3) The fitness costs to the altruist are low. Also defined as Br>C.
Which of the following is not a component of the cost of performing a behavior? Its energetic cost, the risk of being injured, its opportunity cost, the risk of being attacked by a predator, or its information cost.
Its information cost
Alred Russel Wallace
Joint publication with Darwin's On the Perpetuation of Varieties and Species by Natural Means of Selection
Mutation studies (genetic variability underlying trait variability)
Knockout a gene, observe the resulting behavior
Female defense polygyny
Large males may prevent other males from gaining access to females. tends to occur where females are concentrated ex. red deer or elk
Tradeoff between size & number of gametes produced.
Larger size, less mobile. Larger gametes have higher survival.
Conspecific brood parasites
Lay eggs in the nests of other females of the same species, where it will be hard to identify other females' eggs
How is learning ability related to the natural environment of an animal?
Learning is adaptive modification of behaviors based on experience and environment
good reasons to be solitary
Less inbreeding Less infectious disease Less attraction of predators less competition for food and space
What is meant by levels and unit of selection?
Level: individual (interactors) Unit: genes (replicators)
Alpha level
Likelihood of rejecting the null when it is true
Organizational effects
Long term, permanent developmental effects. -Critical periods -Secondary sexual characteristics
Primary sex ratio
M:F ratio at conception (ideally) or at birth (pragmatically). Usually 1:1
Alfred Russel Wallace
Malay archipelago researcher. Contemporary of Darwin. Wrote of natural selection to Darwin and hastened Darwin's Origin of Species publicatio
monogamy
Male and female bond with only one partner. May last only long enough to produce one brood of young (mayflies), or may last a lifetime (swans). A relatively rare mating system.
On the fitness effects level of analysis, why does sexual cannabilism occur from the male and female perspective?
Male redback spider induces sexual cannabilism to ensure successful reproduction and also he may never find another female redback spider. Males usually mate with the female longer if she decides to eat them which means more fertilized eggs. Female perspective of redback spider of eating the male simply because they are hungry.
Which of the following represents a hypothesis on the fitness effects level of analysis?
Male white-crowned sparrows that sing the same song as their neighbors more efficiently deter invasion of their mating territory by their neighbors.
can lead to large variance in male reproductive success.
Male-male competition and Female choice has direct and indirect benefits. Sexual selection doesn't end at mating (sperm competition). Sexual selection can lead to sexual conflict.
On the fitness effects level of analysis, why does sexual cannibalism occur for both males and females?
Male: increase copulation duration Female: receives nourishment
Egg Guarding and Opportunity Costs of Parental Care in Frogs Conclusion
Males attending smaller clutch sizes can achieve a higher fitness benefit by spending time seeking out new mates than guarding eggs.
Lekking in cock of the rock
Males compete for females, each has their own territory (males cluster) females can compare, peck on the neck says "I'm Your's"
Great Reed Warblers
Males defend territories, females visit several before settling, territories have 1-4 females, males provide limited paternal care (usually to first female) -Fit assumptions of Polygyny Threshold model -nest safer in dense weeds (quality of habitat) -Key question: was the RS of secondary females as high as primary females -Yes! (means that polygyny threshold model predicts behavior correctly (never assert it is correct - probably have variables correct BUT still might be better model to explain a certain phenomena) -In Japan, found that females could do better as a secondary female in higher quality nests w/denser weeds
Scramble competition polygyny
Males do not bother to gaurd mates, but instead rush to find another. (can get huge swarms) who: occurs in species (think midge swarms) with explosive breeding, everyone is responding to the same environmental cue. ex. rain ex. male golden toads...now extinct
Lek polygyny
Males provide no resources valuable to breeding females, and no paternal care. females chose among clustered males. can be extremely successful.
Paternity Uncertainty and Male-Only Care in Sunfish (Neff 2003) Hypothesis
Males should reduce care as their paternity certainty declines to avoid caring for unrelated offspring.
Females widely dispersed on sparse resource base..
Males unable to defend more than one female Mating system: monogamy or promiscuity I think monogamy..but might be both
Predation Risk and Parental Care in Golden Egg Bugs Conclusion
Males who exhibit parental care by carrying eggs have higher predation risk.
Paternity Uncertainty and Male-Only Care in Sunfish (Neff 2003) Prediction
Males who observe sneakers near their nest during spawning should provide less care to eggs than males who do not see sneakers near their nests
Mate-assistance hypothesis
Males will remain with a single partner to help rear their offspring in environments in which male parental care can greatly promote infant survival
Mammals and birds have ________ growth and _______ fertilization. Fish, amphibians, and reptiles have ________ growth and ________ fertilization.
Mammals and birds have determinate growth and internal fertilization. Fish, amphibians, and reptiles have indeterminate growth and external fertilization.
How does the mechanism of sex differentiation differ between birds and mammals?
Mammals- males heterogametic sex;refers to the sex of a species in which the sex chromosomes are not the same. bird females are heterogametic
How is the development of these stages regulated?
Many genes evolved in a caste shift share one regulatory mechanism that activates each caste of a bee as neede
How is the development of these stages regulated?
Many genes involved in caste-regulation. Bees have flexibility so they can adapt to the needs of the colony.
True navigation
Map and compass orientation. Knowing where you are in a global (not just local sense)
mobbing behavior
Massive attacks of birds on a predator in order to protect young- a way of increasing reproductive success. Adaptationist approach used to examine this behavior.
Genetic diversity hypothesis
Mating with more males provides more genetic diversity in the offspring and more chance they can adapt to changing environments
Fertility insurance hypothesis
Mating with several males reduces the risk that some of the female's eggs will remain unfertilized due to mating with a partially or completely infertile male
What are some limitations to microarray experiments?
May be many genes responsible for behavior. Jump from genes to behavior is complex.
Gradient in an ESS graph
Measures the selection pressure on a given trait, the steeper the gradient, the stronger the selection pressure. The selection pressure on a trait is determined by how fast fitness changes when we change the trait.
Antipredatory behaviors Subjagation
Mechanical Chemical Group Defense
Natural selection
Mechanism by which evolution occurs. Produces cumulative change, organisms matches environment.
Levels of analysis
Mechanisms (causation) Development Adaptive value (function/utility) Evolutionary history
Sensory filtering
Mechanisms so only respond to relevant stimuli
Clearance of deleterious mutations
Meiosis can make allelic combinations that exclude deleterious mutations. Not all offspring inherit bad mutations. Asexual reproduction cannot separate bad mutations from good ones. Bad mutations can accumulate, but broken apart in sexual species.
Inactivation
Metabolic adaptation. Digest enzymes allow them to break down compounds.
What do the costs relevant to honest expression of male sexually selected ornaments or weapons refer to?
Metabolic or energetic resources that a male must allocate to the growth of ornaments or weapons. The inability of males to invest simultaneously in ornament production and other functions, such as defenses against parasites. The risk a male faces because ornaments slow him down, or because bright colors make him more conspicuous to predators. The fact that time spent displaying to females is time that a male cannot spend searching for food, so the longer he displays, the more he depletes his stored energy reserves and compromises his future survival probability.
What is the mating system of the midshipman fish
Midshipman have two type of males Type I sing to attract females while type II sneak into type I nests and fertilize eggs
What are the two mating systems?
Monogamous and polygamous.
Experimental test: forced monogamy.
Monogamy should remove antagonism. 40 generations later: Semen was less toxic, Females lost their defenses. Females then force to mate with males reared in a competitive environment
Hatch Asyncrhony and Brood Reduction in Blackbirds (Forbes et al. 2002) Prediction
Morality will be highest for late-hatching individuals.
What is the function of stabilamenta in spider webs?
More insects trapped. Avoid wrecking by birds. Increased predation
Material benefits hypothesis
More mates mean more resources or parental care received from the sexual partners of a female
Natural selection
Most powerful mechanism to produce cumulative change and adaptation (match to environment). Works on populations. Confers fitness to offsprin
Cost of being a sexually reproducing female.
Must mate with males. Half of offspring (males) cannot produce offspring. Sex cuts reproducing population in half.
is mate assistance driving monogamy in mammals?
NO evidence for this!!
Is monogamy the norm in human societies? why?
NO!!!! most human societies are polygynous. -males, but not females, gain in terms of progeny via polygamous marriages (see graphs of mormon marriages on slides)
Indicator traits can ...
NOT be cheated, because the trait actually is a good indicator of quality
Kin Selection
Natural Selection that acts through benefits to relatives at the expense of the individual. Decreases the direct fitness of the individual, increases the indirect fitness, resulting in an overall increase in an individual's inclusive fitness.
What is the relationship between evolution and natural selection?
Natural selection is a mechanism by which evolution occurs.
when does it pay (genetically) to help others
Natural selection should favor an altruistic behavior if C < rB. Natural selection should disfavor it if C > rB. Coefficient of relationship between the two individuals (r) Cost of the action to the altruist (C) Benefit of the action to the recipient (B)
kin selection
Natural selection that acts through benefits to relatives at the expense of the individual.
What ultimate processes shape the tuning curve for any given sensory syste
Natural selection/evolution, what the organism needs to hear in order to survive Ultimate processes: function (sensory systems necessary for surviv
Why does dead reckoning require a compass and an odometer?
Need compass for directionality. And since theses animals do not have a global sense they need an odometer sense to determine how far they are from home.
Why might consciousness be adaptive for highly social species
Need to be able to attribute mental state to other individuals to predict their behavior
What are the general neurological mechanisms behind a central pattern generator?
Neural clusters labeled as central pattern generators send a set of preprogrammed messages and signals that help organize motor output into a specific patt
Action potential
Neural signal
The field of ethology was jump-started using evolutionary theory applied to animal behavior by the following people, who shared the Nobel Prize in 1
Niko Tinbergen, Konrad Lorenz, and Karl von Frisch
isogamy
No true male or female; gametes are morphologically identical Eg. Chlamydomonas
Are all activities correlated with environmental cues the result of biological clocks?
No. Another theory is that animals alter the relationship among command centers in their nervous systems on the basis of feedback info gathered by monitoring the surrounding environment.
Can ESS be achieved?
No. But if it ever was it could not be displaced.
Common garden experiments
Observation: 2 different phenotypes in individuals Hypothesis: Differences due to genetic differences Test: raise 2 offspring in same, controlled environment. Any differences must be due to genetics. Example: garter snake feeding
Scientific method
Observations Questions Hypotheses Predictions Tests Statistical analysis Intepretation
the scientific method
Observations = natural phenomena - Questions = How and Why - Hypotheses = potential explanation, alternatives (falsifiability) - Predictions = If....then (specific tests) - Tests = experiments or observations - Statistical analysis - Interpretation • Hypothesis supported or rejected? • Alternative hypotheses?
Common garden experiment
Observe different phenotype in at least two different individuals in same environment, hypothesis is difference is caused by underlying genetic differences not environment
Life History Variation in Fish (Vila-Gispert et al. 2002) Methods
Obtained life history data for 300 species, including: • Age at maturity • Maximum body size • Length of breeding season • Number of reproductive events per year • Average egg size • Fecundity • Level of parental care
Self-fertilization
Occurs in hermaphroditic organisms when the two gametes fused in fertilization come from the same individual. Although this is still sexual reproduction (because it incorporates meiosis and fertilization), it yields offspring that are lacking in genetic variation.
Intrasexual Selection
Occurs when members of the less limiting sex (generally males) compete with each other over reproductive access to the limiting sex (generally females). Often called male-male competition.
Intersexual Selection
Occurs when members of the limiting sex (generally females) actively discriminate among suitors of the less limited sex (generally males). Often called female choice.
Code-breaker
Once a sensory system evolves to respond to a particular stimulus it can be co-opted/exploited
Monogamy
One male and one female have an exclusive mating relationship.
Polygyny
One male has an exclusive relationship with two or more females. a} This is the most common polygamous mating system in vertebrates.
Monogamous mating systems:
One male pairs with one female.
Lifetime monogamy
One mate for life
Serial monogamy
One mate per breeding season
Karl Von Frish
One of the founders of Ethology, honeybee social organization communication sensory perception "waggle dance" they can see some color
Konrad lorenz
One of the founders of ethology did work on gentricall programmed behavior and concepts of imprinting and critical periods
Paternity Uncertainty and Male-Only Care in Sunfish (Neff 2003) Conclusion
Parental care by male bluegill sunfish is affected by their certainty of paternity
Fecundity
Reproductive rate of an organism, measured by the number of gametes that are available by the male or the female
What is the genetic/molecular mechanism underlying circadian rhythm
Optic lobe tells the amount of daylight and adjust cycle according
Brood parasitism
Organisms that rely on others to raise young, like Cuckoos
How can ornaments signal quality?
Ornaments must be honest if it is continuously favored by selection. Costly, But can indicate that the individual is strong enough to deal with it. Good genes passed on to offspring.
How is Fighting parasitic infection An evolutionary arms race between hosts and parasites.?
Parasites specialize on the most common genotypes in host populations. Negative frequency-dependent selection results in cycles of common and rare genotypes. Sexual reproduction enables more rapid counter adaptation to parasites.
What is the neurological mechanism in birds underlying perception of photoperiod?
Photosensitivity
Why do pursuit-deterrent signals benefit both predator and prey?
Predator: does not have to wast energy chasing prey Prey: does not have to outrun predator
predator satiation
Predators can only consume a certain amount of prey, therefore prey will benefit from being at high densities or in large groups. see dilution effect
How does predator behavior affect the evolution of color polymorphism in cryptic prey?
Predators have evolved detection mechanisms (search images). Prey evolved color polymorphism to make it harder for predators to detect them (selective response to search images).
Aggressive mimicry
Predators share signals with harmless model (prey) to avoid detection
pursuit deterrence signal
Prey indicates to predator that pursuit would be unprofitable because the signaler is prepared to escape
How do predators or parasites affect optimal foraging decisions?
Probability of being eaten or parasitized affects optimality. Tradeoff of foraging success vs predation
Multiple matings are also costly at the individual level...EPCs increase the risk of STDs, but are there counter adaptations?
Probability of sperm-transported disease would increase when females are mating with more males Probability of menstruation increases...health compensation? no not true
Relatedness
Probability than the same allele is present in two individuals because of a common ancestor
Communication
Process in which sender uses evolved signal to modify behavior of receiver
An individual with mutation A and an individual with mutation B mate.
Produce offspring with AB genotype, which has higher fitness. at a faster rate than asexual reproduction.
anisogamy
Production of two types of gametes of different sizes. heterogamy
Prolactin and Incubation in Penguins (Massaro et al. 2007) Prediction
Prolactin levels will be higher when penguins receive visual (sight of an egg) and tactile cues (feeling of egg on the brooding patch).
Prolactin and Maternal Care in Rats (Bridges et al. 1990) Conclusion
Prolactin strongly affects parental care in female rats.
Heritability
Proportion of phenotypic differences due to genotypic differences
Heritability
Proportion of phenotypic variance due to genetic differenc
Predation Risk and Parental Care in Golden Egg Bugs Hypothesis
Providing care to eggs can increase predation risk.
Levels of Analysis (types)
Proximate (within an individual) and Ultimate (within a population/species)
What is the explanation for why birds have song dialects at both proximate and ultimate levels of analysis?
Proximate: -Geographic variation due to either genes or environment -Critical period for song learning Ultimate: -Females prefer larger repertoires -Male to male competition, fewer intruders if it sounds like a male is still present -Help distinguish between friends and enemies
What basic principles of experimental design and statistical analysis were illustrated by the termite trail following experiment?
Randomization · Standardization · Blind to treatment · Control Binomial test
How would you graphically represent the ideal free distribution?
Reproductive success vs number of other birds
How does eavesdropping affect signal design and evolution?
Receiver benefits while costly to sender.
Sensory exploitation
Receivers have preference for particular signal, which is exploited by senders
Meaning
Receivers perception of a message
Why can sexual reproduction speed the spread of adaptations in a population?
Recombination can lead to novel genotypes and beneficial mutations can be combined and harmful mutations can be purged.
What is the likely evolution of the dance language?
Recruitment for quick and efficient foraging. Direction -Start with guide -Guide gets lazy -Dances to point way Distance -Start as agitated buzzing -Standardized sounds and movement -Symbolic information
Ritualization
Refinement of inadvertent cue into true signal
Handicap signals
Reliable signals that are costly to the sender
What is the typical experimental strategy for determining the effects of a hormone?
Remove hormone/organ producing hormone, see if behavior stops, add hormone see if behavior returns to normal
How is a genomic approach useful for identifying the genetic basis for these behavioral stages?
Researchers can identify genes involved in specific social interactions. And see how they are up or down regulated based on changing conditions
What is the physiological basis for TTX resistance in garter snakes, why does it cost a highly tradeoff?
Resistance to TTX is caused by a mutation in the sodium channel, which makes these snakes much slower
Why do territorial holders usually win contests with intruders?
Resource holding power -Territorial animals are higher quality Asymmetrical Benefits -Territory more valuable to holder -Familiar with territory -Dear enemy
Message
Senders perspective of information exchange, core of information content
What are some ways you could define consciousness experientially?
Sleeping -Awake: conscious -Asleep: unconscious Growing Up -Baby: unconscious -Adult: conscious
What are some ways you could define consciousness experiential
Sleeping- awake and aware conscious asleep= unconscious Can also be defined ontogenically e.g. Adults= conscious children = unconscio
Optimality and Modeling
Robert H Mac Arthur those organisms that do thing best (most efficiently, safely ect.) will tend to prosper
How does the dance language of honeybees work?
Round Dance -Less than 50m from hive -No directionality Waggle Dance -Length indicates distance -Angle indicates direction
Antipredatory behaviors Approach and attack
Run Hide Startle Confuse Bluff Threat
Crested Auklet
Sea Bird related to Puffins, colonial nest in Alaska. wick feathers on their backs that secret scent like a tangerine 2 hypotheses 1.social mate choice, more oil secreted better neck rubbing partner 2. insect repellent function
Brood Reduction in Fur Seals (Trillmich & Wolf 2008) Prediction
Second offspring should suffer high mortality in years of scarce resources and have high survivorship in years of abundant resources.
How would you distinguish a dilution effect benefit from a selfish her benefit?
See if there is a preference for a certain position (this would indicate selfish herd). Dilution assumes equal chance of capture Selfish herd assumes unequal chance of capture
Example of sensory exploitation
Sensory exploitation model (Mike Ryan 1990): Suppose female butterflies prefer to forage on red flowers; because the only time females encounter red is with flowers, it may prove most efficient to evolve a general preference for red objects Feeding: females have preference for red objects Mating: males evolve red coloration to "exploit" preference a male signal could evolve with no historical link to the specific context (mate choice) but only to another currently irrelevant context (foraging). -if females benefit from a new signal, then it's stable -if it's costly, then females selected to differentiate between mating and feeding
Umwelt
Sensory system for a species defines its umwelt
Tuning Curve
Sensory threshold intensity frequencies for a single neuron. Neurons must encode at the peak of the tuning curve.
Klinotaxis
Sequential comparisons with movement of single sensor
Sound production in moths
Seven species of moths have evolved the ability to produce ultrasonic sounds -ultrasonic sounds are used to either interfere(jam) bat calls or communicate with other moths of same species. Ultrasonic communication: male whistling moths produce ultrasounds by striking the knobby "castanets" (arrow) on their forewings together. Main point of this example: theses animals took advantage of their pre-adaptation to detect ultrasound and invested in an apparatus for acoustic communication.
Habitats of New Zealand snail with both sexual and asexual forms.
Sexual form is more common in habitats with more ecological niches like lakes. than those with few niches such as streams.
Universals of Attractiveness: 3. Parental traits
Sexual imprinting in humnas?? -two studies have shown a positive correlation between father's age and the daughter's partner's age -women born to older fathers tend to marry older men. the positive relationship between father's and partner's age is positive and significant when the age and education of women is held constant. Suggests the possibility of imprinting. -daughters may imprint on the visual characteristics of their father (such as age-related characteristics) as children and later find these characteristics preferable in their own partner.
Anisogamy
Sexual reproduction involving the fusion of two dissimilar gametes; individuals producing the larger gamete (eggs) are defined as female, and individuals producing the smaller gamete (sperm) are defined as male.
Anisogamy:
Sexual reproduction involving the fusion of two dissimilar gametes; individuals producing the larger gamete are female, and individuals producing the smaller gamete are male.
Sexual selection is typically stronger on what sex? and why?
Sexual selection is typically stronger on males. Maximize fitness by mating multiply. Male biased operational sex ratio. (OSR)
divergent evolution
Shared ancestry with similar genetic heritage and different attributes because of different selective pressures
Signal
Specially evolved by natural selection (more specific than a cue)
Code-breakers
Species that have evolved to exploit the FAP of another species Example: wasp mimics chemical signal of Butterflies so that ants care for their larvae
Life History Variation in Fish (Vila-Gispert et al. 2002) Conclusion
Species that invest more in individual offspring (large egg size) tend to also provide greater levels of parental care.
What does Altricial development refer to?
Species where the young that are born or hatched are not immediately fully developed, nor are they mobile
What does Precocial development refer to?
Species where the young that are born or hatched are practically fully developed and are immediately mobile
What happens when females mate with multiple males?
Sperm from the different males must compete for opportunities to fertilize the females' eggs.
Principal component analysis
Statistical procedure that converts a set of possibly correlated variables into a set of values of linearly uncorrelated variables called principal components.
What is intragenomic conflict and why might it sometimes occur?
Struggle in genome. Genes do not follow traditional rules of inheritance. A gene may transmit itself at the detriment of other genes. And example of this is meiotic drive in fruit flies (results in 100% daughters)
How does landmark navigation work?
Taxis (orientation and movement with directionality) using landmarks
Brood Reduction in Fur Seals (Trillmich & Wolf 2008) Hypothesis
Survivorship of pups with an older sibling is related to resource availability.
conditional strategy theory
Tactic is chosen based on a higher fitness yield given a certain social status.
comparative method
Testing predictions about the evolution of a trait by looking at species other than the one whose characteristics are under investigation.
Does testosterone have activational, organizational, associated or dissociated effects (and why is this a trick question)?
Testosterone can have both organizational and activational effects as well as associate and dissociated depending on the situation and the species. · Sex determination- birds-organizational · Recover from castration - guinea pigs · Male behavior stop with castration starts again with T implant- quail · T primes mating for later- garter snakes
Why are biological clocks entrained on environmental cu
That way when environmental factors change the organism can adjust to new schedule
What does antagonistic coevolution refer to in the context of sexual selection?
The arms races that can result as males and females compete for control over fertilization.
Cooperation and Mutualism
The benefits of assisting others exceed the costs. When cooperation occurs among individuals, mutualism is said to occur. Both organisms benefit.
Genetic Load
The burden imposed by the accumulation of deleterious mutations.
Inclusive Fitness
The combination of direct and indirect fitness components
inclusive fitness
The combination of direct and indirect fitness components.
Sex
The combining and mixing of chromosomes during the formation of offspring. It involves two main processes: (1) meiosis halves the number of chromosomes during gamete formation, and (2) fertilization restores the original chromosome number as two gametes fuse to form a zygote.
adaptive value
The contribution a gene or trait makes to inclusive fitness.
the cost of sex
The cost of meiosis The cost of anisogamy Genetic load The cost to sibling altruism
Brood reduction
The death of some siblings as a result of reduced parental care for the purpose of enhancing fitness of surviving siblings
Adult male dogs life a hing leg when they urinate, whereas young puppies and adult female dogs squat. If a newborn male puppy receives an injection of estrogen, it will never lift its leg to urinate; for the rest of its life, it will always squat. How might this result be explained?
The development of brain circuitry controlling the sexual dimorphism in urination behavior is influenced by the levels of estrogen or testosterone that are circulating in the blood during the early postnatal period. Estogren must prevent the development of the neuronal patterns of connectivity that are responsible for the male behavior.
We observe variation in a population of lizard with respect to how fast individuals can run. We attempt to select for the ability to run slowly, not quickly. After six generations of selectively breeding only the slowest with the slowest, the mean running speed of the lizards did not change. What is the best conclusion based on this work?
The differences between the lizards in running speed in the original population were not caused by genetic differences among them
Sexual conflict
The differential selection on males and females to maximize their fitness
Twofold Cost of Sex
The disadvantages of being a sexual rather than asexual organism. Asexual lineages multiply faster than sexual lineages because all progeny are capable of producing offspring. In sexual lineages, half of the offspring are males who cannot themselves produce offspring. This limitation effectively halves the rate of replication of sexual species.
What is an example of anisogamy?
The eggs of a female kiwi are large ,but the sperm of the males are small.
What are ecological situations that require rapid and continuous evolution likely to favor?
The evolution and maintenance of sex.
Sexual Conflict
The evolution of phenotypic characteristics that confer a fitness benefit to one sex but a fitness cost to the other.
What is the Red Queen Effect used to explain?
The evolution of sexual reproduction, because sexually reproducing organisms are likely to fare better in the continual evolutionary arms races that can arise between species (e.g., between parasites or pathogens and their hosts).
Opportunity costs
The fitness costs of not engaging in other activities.
Reproduction
The formation of new individual organisms (offspring).
Eusociality: 3 requirements
The highest level of social organization in animals 1. there is cooperative brood care 2. division of labor 3. overlapping generations
resource holding power
The inherent capacity of an individual to defeat others when competing for useful resources.
home range
The living space of a particular species or organism.
The mode of fertilization affects __________ and indeterminate growth affects _________.
The mode of fertilization affects paternity certainty and indeterminate growth affects fecundity.
How does the star nose enable the mole to occupy a unique ecological nich
The mole is able to detect and get small insects with high efficiency/low handling time, which allows it to grab prey that other insectivores in the same environment would ignore.
What is a female's reproductive success often limited by?
The number of eggs that she can produce and provision. Females with access to the most resources generally achieve the highest egg (and offspring) numbers and have the highest fitness relative to other females.
What is male reproductive success often limited by?
The number of matings the male can obtain. Males who mate with the most females generally sire the greatest number of offspring and have the highest fitness relative to other males.
What can the variance in reproductive success of males and females influence?
The opportunity for sexual selection.
How does the experiment by Seed et al. (2006) experimental design allow them to discriminate associative learning from an understanding of causal mechanism
The original setup for experiments of this design were flawed by the fact that animals could learn to associate results with simple rules (e.g. rule of thumb). Seed et al. changed this by walking the crows through a series of simple traps, then, constructed a complex trap where the only way they could solve the problem and get the food reward would be to incorporate what they had learned from the simple traps and apply the underlying mechanisms to the complex trap. there was no association for them to recognize and utilize. This was how they determined whether or not the crows were merely learning by association or truly understanding the cause and effect mechanisms that went into these traps
Parasite host relationship in asexual and sexual reproduction.
The parasites are likely to be very successful, since in each generations, their host's genome remains largely unchanged. But the generation of genetic variation due to sexual reproduction creates a moving target for parasites, and will enable the host to keep pace with the parasites.
Polygyny threshold model
The point at which a female will benefit more by joining an already mated male possessing a good territory rather than an unmated male on a poor territory
What characteristic is shared by all eusocial species?
The presence of sterile classes
Certainty of Paternity
The probability that a male as the genetic sire of the offspring his mate produces.
Why is it important that alternative hypotheses are on the same level of analysis?
The problem is that when you ask questions that are on two different levels then you just pass over each other. You analyze a behavior in 4 separate levels which are not really related to each othe
Muller's ratchet:
The process by which the genomes of an ASEXUAL population accumulate deleterious mutations in an irreversible manner.
Muller's Ratchet
The process by which the genomes of an asexual population accumulate deleterious mutations in an irreversible manner.
Operational Sex Ratio (OSR)
The ratio of male to female individuals who are available for reproducing at any given time.
Operational sex ratio:
The ratio of male to female individuals who are available for reproducing at any given time.
Fecundity
The reproductive capacity of an individual, such as the number and quality of eggs or sperm. As a measure of relative fitness, this refers to the number of offspring produced by an organism.
What ultimate processes shape the tuning curve for any given sensory system?
The sensory threshold intensity at varying frequencies. Only respond to relevant stimuli. Pattern of response can give clues to ultimate cause of behavior.
What sex does sexual selection affect?
The sex with the greater variance in reproductive success (usually males).
The sex with the _______ cost of care should provide less care because its net benefit of care will be _______.
The sex with the higher cost of care should provide less care because its net benefit of care will be smaller.
What is the function of a star nose, and how is analogous to an eye
The star nose allows the mole to detect small insects with tactile sensors in each arm. Each of the arms is able to detect the things around it, giving the star mole a "picture" of its environment much like an eye
What is the function of the star nose? How is it analogous to an eye?
The star nose, is like the eye for the mole. It decreases the handling time of small prey, to make them profitable. It is analogous to an eye because it is tactile "vision" for the mole.
Key idea for ESS
The success of a new mutant depends on the environment in which is emerges.
inclusive fitness
The sum of an individual's own reproductive success plus the effects the organism has on the reproductive success of related others.
Opportunity for selection:
The variance in fitness within a population. Opportunity for selection constrains the intensity of selection that is possible.
Opportunity for Selection
The variance in fitness within a population. When there is no variance in fitness, there can be no selection; when there is large variance in fitness, there is a great opportunity for selection. In this sense, the opportunity for selection constrains the intensity of selection that is possible.
Why do desert ants employ dead reckoning rather than landmark navigatio
There are not very many landmarks in the desert on that fine of a scale. Ants use dead reckoning in order to navigat
Juvenile Hormones and Parental Care in Earwigs (Rankin et al. 1995) Conclusion
There is an inverse relationship between juvenile hormone level and female care behaviour species.
What do people mean when they say "there is a gene for behavior X
There is genetic variation underlying variation in X, probably environmental variation in on X as well
Why is it important that alternative hypotheses are on the same level of analysis?
There may be falsely competing hypotheses if they are on different levels of analysis
Why are traits like the bright colors of a male manakin considered to be honest indicators of male genetic quality?
They are very costly for males to produce.
Some women carry "selfish" genetic elements that cause them to only give birth to daughters, as sperm carrying a Y-chromosome are killed. Which of true of these genetic elements
They can evolve despite not being favored by natural selec
How do monarchs orient during migration, why do they migrate, and why is this example perplexing (when compared to bird migrations, say)?
They use UV and polarized light, even when the sun is covered in clouds monarchs are able to tell direction. Also the same butterfly does not make a full rotational migration it is done over 5 generati
How do sea turtles find their way back to their breeding locations?
They use the magnetic field
Reflective cnsciousness
Thinking about thinking
Perceptual consciousnes
Thinking about you environment
Why might the fact that humans live in social family groups affect the way we treat other species?
This is because we can be biased. We treat species a certain way if they are more like us or not.
Displacement acts--courtship in the great crested grebe example
This part of courtship (penguin dance) evolved from displacement nest building. the mate dive for weeds to present to one another.
How do studies of Darwin's finches show natural selection in action
This shows natural selection in action because there were different beak sizes depending on season. If there was a drought then the seeds were large and only the finches that were able to eat these seeds would survive and these were finches with large beaks.
Predation Risk and Parental Care in Golden Egg Bugs Research question
What is the cost of egg carrying?
Why does changing the size of the zone of orientation of individual fish in schools affect the collective response to a predator?
Too Small: individuals move independently, fractionation Too Large: too much information, uncoordinated movements
Ornaments.
Trait that enhances appearance of an animal, sometimes detriment of survival.
Convergence stability
Traits closer to the ESS than the current resident can invade. It ensures the gradual approach through a series of small evolutionary steps.
Life history traits
Traits involved with growth, reproduction, and survivorship
Armaments.
Traits such as horns, antlers, spurs, and big-strong body.
Sensory neurons
Transfers from sensory cells to the CNS
Paternity Uncertainty and Male-Only Care in Sunfish (Neff 2003) Results
Treatment males exhibited significantly lower levels of defense behaviour than did controls.
How do treehopper bugs provide parental care?
Treehopper parental care involves egg guarding by females, but this behaviour varies among individuals.
Activational effect
Triggering usually short term, reversible
Anisogamy in the Kiwi bird.
Trillion sperm can be produced with similar amount of energy to produce a single egg
One advantage of pheromones is that the message can persist over time. True or False.
True
Regarding animal orientation: the stars offer two sources of information about direction: a fixed point and moving constellations. True or False.
True
True or False: Behavior is just like any other phenotype in that it can evolve by natural selection.
True
another example of exploitation (eavesdropping)
Tuning curves of the parasitiod fly (ormia ochracea) -female Ormia flies eavesdrop to the calls of male crickets with produce a frequency power spectrum that peaks between 4-5 kHz -the female fly seeks out the male cricket as host for its young!!!! -directional hearing in Ormia: -->female ormia flies use their auditory sense to locate male crickets which are often used as hosts for the fly's young!
How does the organizational cascade differ between type I and II midshipman?
Type II take longer to reach sexual maturity. Relative size of fish at initiation of hormonal cascade determines type
Polygynandry
Type of polygamy, where two or more males have an exclusive relationship with two or more females;
what are the types of polygyny?
Types of Polygyny: 1. Scramble Competition 2. Mate defense 3. Resource defense 4. Lek
What are the two types and four levels of analysis?
Types: Proximate and Ultimate Levels: Mechanism, Development, Adaptive value, Evolutionary history
Universals of attractiveness: 1. Body shape
UT Austin study examined women's wait-to-hip ratio (WHR) -women with a WHR of 0.7 (indicating waist significantly narrower than hips) are more desirable to men -an analysis of hourglass figures of playboy models and Miss America contestants showed that most of these women have a WHR of 0.7 or lower. -in general, a range of 0.67 to 1.18 in females is attractive to men, while a 0.8 to 1.0 WHR in men is attractive to women, althought having broad shoulder is more of a 'turn-on'
Under what conditions are honest signaling interactions forced versus unforced?
Unforced -Interest of sender and receiver congruent -Mutual for both parties -Bee dance language Forced -Interest of sender and receiver incongruent -Courtship -Predation -Fighting
why polyandry is rare
Unpredictable food supply Intense predator pressure Male control of valued resources
How do sea turtle find their way back to breeding locations?
Use magnetic fields. Can sense the position of magnetic poles relative to their breeding ground.
Can you clarify the level of analysis for a particular hypothesis (like our examples for the first lecture)?
Vampire bats share blood consumed with other bats that did not get any while foraging. This is a study under the ultimate type of analysis and under the functional level because this sharing increases the overall survivability of the population of vampire bats thus increasing their fitness.
What evidence indicates the maintenance of venom resistance in squirrels is costly?
Venom resistance is lost under relaxed selection, rapidly acquired in high snake dense areas.
How is heritability measured? Why is it difficult to generalize heritability values?
Vg/(Vg+Ve). Parent-offspring regression. It is difficult to generalize these values because they are environment-specific, most behavior is too complex to measure genetic contribution.
How might animal consciousness be analogous to an eye?
Vision is peripheral with fovea to focus Like vision across taxa, consciousness also varies in ability Most thinking is unconscious with conscious for focusing
Prolactin and Incubation in Penguins (Massaro et al. 2007) Conclusion
Visual and tactile stimulation together result in increased prolactin levels, increased maternal care, and development of a larger brood patch.
Chemicals in Drosophila semen
Wards off other male sperm, but are toxic to females. Females produce proteins that destroy some of the toxic proteins. Males and females are in an arms race.
What do warm water temperatures mean in relation to food abundance for fur seals?
Warm water temperatures (upwelling) result in a food scarcity for seals, however the climate is unpredictable.
aposematism
Warning signal, usually coloration, of toxic organisms. Antithesis of crypsis.
Why might the fact that humans live in social family groups affect the way we treat other species?
We are conditioned to treat other species the way we treat other humans. Rank importance based on sentience and similarity to ourselves
Prolactin and Incubation in Penguins (Massaro et al. 2007) Research question
What is the proximate mechanism that causes the increase in blood prolactin levels during egg laying?
Conspecific Brood Parasitism in Ducks (Ahlund & Andersson 2001) Research question
What reproductive strategy leads to the highest fitness (pure parasite, nesting parasite [mixed strategy], or nonparasites)?
Amplexus
When a male grasps and holds a female prior to copulation
give an example of a human society practicing resource defense polygyny
Wealthy men have more children polygynous Yomut of Iran
Paternity Uncertainty and Male-Only Care in Sunfish (Neff 2003) Research question
What affects the level of male parental care in bluegill sunfish?
Evolutionary Stable Strategy
When no new mutant can invade. Mutant strategies have a lambda value of less than 1, whereas the resident strategy has a lambda value = 1.
Prolactin and Incubation in Penguins (Massaro et al. 2007) Hypothesis
When provided with visual and tactile cues of an egg's presence, blood prolactin levels will change.
How does Hamilton's Rule explain the favoring of self-sacrificing behavior by natural selection?
When this rule holds, alleles associated with altruistic behavior will be favored by natural selection because close relatives are very likely to have copies of the altruistic alleles, increasing the alleles within the population.
inbreeding depression
When two closely related individuals mate, the offspring are more likely to carry damaging recessive alleles in double does than are offspring produced by unrelated pairs.
polyandrous mating systems:
Where females mate with multiple males.
Resource dispersion-female dispersion and the evolution of mating systems
Who's interested in what? Female reproductive success limited by quality Male reproductive success limited by quality Males have to eat, but they also need to look for females to mate with, so male dispersion is going to be highly influenced by female dispersion Females need resources for their young, and resource patterns affect where they disperse, also predation (also B/C of sociality)
Brood Reduction in Fur Seals (Trillmich & Wolf 2008) Research question
Why do female fur seals give birth in two successive years?
territoriality
Willingness to defend land against intruders especially for the purposes of breeding.
Proximate
Within an individual -about mechanisms -causation: external stimuli, sensory, nervous system, etc. -about ontogeny = during development of behavior during an indiv.'s life ,learned
Eusociality
Workers sacrifice most or all of their direct reproduction to help rear the queen's offspring 1.Group Living 2. Overlap of at least 2 generations 3. Reproductive division of labor 4. Cooperative care of young
What about other non-physical traits? Other Sex Differences in Mate Selectivity Are there sex differences int he standards of min. intelligence of a partner with respect to having sex??
YES and NO!! College men differ from college women in the minimum intelligence for having a casual sexual vs marriage partner.
Can females control whose sperm they use to fertilize their eggs?
Yes. In these species, males may continue to court females even after they have finished mating.
Polygyny in humans?
Yes. Kipsigis people of Kenya. After European colonization of Kenya, Kipsigis emigrated into areas previously occupied by Masai tribe. Borgerhott-Mulder (1988, 2990) examiend settlement patterns... -How large a territory did a male settle in? -How many wives did a male take to new territory? -How many wives did he "obtained" after settlement? Results: -men with larger territory obtained more wives -cost of polygyny: female reproductive success declined with increasing number wives -if territory sizes same, women preferred bachelors to married men. *supports prediction of Polygyny Threshold Model
Are unequal gamete sizes relevant for explaining adult behavior?
Yes. There typically are insufficient eggs to go around; males end up having to compete for access to them.
What are some of the current limitations of this technique
You have identified some genes that may be involved in the expression of particular behavior; many other genes involved too, but you can't tell what they are (yet). The relationships between the gene products and the behavior itself are still kind of a black box. Sometimes head-scratching genes emerge (neurospin linked to exploratory behavior in rats?)
How does the collective movement of fish schools result from simple behavioral rules?
ZOR (zone of repulsion): maintain a close distance with neighbors while avoiding collision ZOO (zone or orientation): align with others ZOA (zone of attraction): attracted to others within this zone
mutualism
a +,+ interraction in which both species benefit
commensalism
a +,0 ecological relationship in which one species benefits from another species, which is itself not affected one way or the other
mate guarding
a behavior displayed by an individual that reduces the opportunity for that individual's mate to interact with other potential mates -dragonflies and damselflies (male flying around holding onto the female!) -->end up having fewer of other males' young in the nest if this behavior is displayed
maladaptive
a behavior or trait that is counterproductive to the survival or well-being of an organism
what is encoded in the hip ratio?
a big "fat" clue to whether the person will have enough energy to care for offspring -fat deposited on the body is determined by sex hormones; testosterone in men, and estrogen in women. -if a woman produces the proper amount and mixture of E, then her WHR will naturally fall into the desired range. -people in the ideal hip-ratio range, regardless of weight, are less susceptible to disease such as cartiovasccular disorders, cancer and diabetes, studies have shown. -women in theis range also have less difficulty conceiving
why doesn't selection favor males that "cheat"? ex: why can't males with relatively poor genes simply grow a large peacock tail with many eyes?
a deceptive peacock: bad genes in good clothes? answer: Zahavi's Handicap principle
frequency dependent selection
a decline in the reproductive success of individuals that have a phenotype that has become too common in a population
intrasexual selection
a direct competition among individuals of one sex (usually the males in vertebrates) for mates of the opposite sex
Sexy son hypotheses
a female that chooses to be the second female of the polygynous male will have sons that are more attractive or successful -secondary females should have greater reproductive success that a monogamous female -polygynous "sexy fathers" should have physical attributes different from those of monogamous males...dull males considered unsexy, bright males considered sexy
Polygyny threshold Hypotheses
a female that choses to be the secondary female of a polygynous male should do as well or better than she should do as well or better that she would by being the sole mate of a monogamous male -polygyny will occur on territories with the richest resources -secondary females will have reproductive success greater than or equal to that of monogamous females in lower quality habitat ....see graph=shoes that at a certain environmental quality (x) the fitness (y) for a secondary female is more than or equal to a monogamous female
nuptial gift
a male provides a female with valuable nutrients/food or chemical compounds
Polygynandry (promiscuity) and example
a mating system that includes multiple males and multiple females. Example: bonobos: take part in both homosexual and heterosexual interactions, females will mate with anyone except for their sons
female defense polygyny
a mating system where males mate with many females, and defend females from mating attempts by other males
brood patch
a patch of skin
female polyandry. rare pattern. why have it then? list possible reasons.
a) fertility insurance b) genetically compatible sperm c) good genes d) material benefits
Why don't all senders exploit these biases?
a) phylogenic constraints b) necessary mutation does not occur c) selective pressures differ between species
Proximate type 1
about mechanisms (level 1) -causation: external stimuli, sensory, nervous system, etc. -about ontogeny (level 2) - during development of behavior during an indiv.'s life
is body shape correlated with fertility in women?
according to study: men prefer (narrow waists and large breasts) which is most characteristic of fertility based on body shapes of a sample of healthy Polish women between 24-37 years old. *so "beauty" can convey information about health and fertility
adaptation vs expatiation
adaptation: trait evolved for the purpose its currently used for expatiation: natural selection sometimes have phylogenetic constraints
copulatory plugs
after mating, male secretion form a barrier so that other males are unable to mate with her - decreases a females fitness
Honesty Agonistic Signals
agonistic signals can be honest indicators- body size limits lowest frequencies produced by sender example: agonistic growl vs. snort of dogs -dogs (like most othe rvertebrates) favor harsh low freq sounds as threats and high frets to indicate submission -the growl (w/ lower freq) vs. the mort will allow for honest assessment of relative body size and allow receiver to rival.
How did researchers determine the % of men descended from King Niall of the 9 hostages?
all carried a unique motif on the y chromosome indicating they were descended from King Niall
Which of the following is a cue that an animal would use in selecting a field in which live? Presence of food, presence of conspecifics, reproductive success of conspecifics the previous year, presence of nest sites, or all of the above.
all of the above
1)Alternation
alternation of intention movements classic examples=zigzag dance of the male stickleback during courtship
Chinchillas
altricial
Ferrets
altricial
Gerbils
altricial
Hamsters
altricial
Hedgehogs
altricial
Mice
altricial
Rats
altricial
Altricial vs. Precocial
altricial means naked and helpless at hatching, while precocial means covered with down and able to run or swim almost immediately after hatching
motivational conflict: Ambivalence Behavior
ambivalence behavior= reflects the animal's indecision over which of two opposing motivational systems to, and can result in either 1)ALTERNATED or 2)BLENDED displays
Triver's Parental Investment Theory
amount of energy parents put into producing and raising their offspring. Making gametes, gestation period and parental care. The sex making the largest investment in forming, nurturing and protecting offspring will be more choosy in picking their mate because they want the best offspring they can get. The sex that invests less in offspring will compete for access to the higher investing sex.
predator saturation effect
an antipredator adaptation. a safety in number effect where n which prey occur at high population densities, reducing the probability of an individual organism being eaten
Sensory bias
an existing bias in the sensory system. males that exploit this may be easier for females to notice. Can launch evolution of sexual ornament
genetic quality
an indicator of good genes (potential fitness) usually in males.
cooperation
an outcome from which two or more interacting individuals each receives a net benefit from their joint actions, despite the potential costs they may have to pay for undertaking such actions
bipedal
anatomy which leaves the wings free for flying
inclusive fitness theory
animals take into account both direct and indirect fitness
why does sexual selection exist?
anisogmy and operational sex ratio (OSR)
migration
annual moving to a different region
Polyandry
another form of polygamy. Female bonds with multiple partners at once. Eg. Jacana and common sandpiper Very rare.
talk about unritualized autonomic responses give examples
any autonomic response (unritualized) can be potentially controlled to produce a signal often associated with fear or excitement level examples= feather sleeking in birds, sweating in humans --> "social smells modulate vision in an emotion-specific way"
Brood parasites
are organisms that use the strategy of brood parasitism.
what assumption was made in the study of sexual dimorphism levels in XY and ZW animals?
assume that sexual dimorphism is related to selection for ornamentation
what is the average reproductive success of males and females when there is a 1:1 sex ratio?
average reproductive success will be the same in males and females
If you were interested in studying the production of new neurons in the brains of adult vertebrates, what area of study would be the best place to start?
avian singing behavior
Signal Evolution: Origins How do communication signals actually arise?
both parties (sender and receiver) must pay some initial costs to communicate, but losses are eventually recuperated through benefits of the receiver's response. One or both parties must first evolve precursors of their eventual signaling role for reasons other than communication. Others then take advantage of the pre-adaptation and invest in an apparatus to complete the exchange of communication signals. ex: noctuid moths
Relatedness
how many gene copies one organism shares with anot
How do arthropods such as parasitoid wasps adjust the sex of their egg?
by choosing to fertilize the egg or not (haplodiploidy means unfertilized eggs will grow up as males)
a species mating system is defined by what?
by the patterns in mating frequency for each sex.
Why two types of gametes?
because they have been favored by natural selection, one for mate finding and another for mate survival.
reciprocal altruism
behavior that benefits another with the expectation that those benefits will be returned in the future Eg Vampire bats
Air Sacs
behind lungs
Direct Benefits
benefit that is going to the female when choosing a mate
carotenoid plumage color in house finches
cartenoids cannot be synthesized, so their display by males provides an honest measure of a male's foraging ability -redder males provide more -coloration is heritable.... so leads to sexy sons
extrapair fertilizations (EPFs)
cases where offsprings biological and social father do not match. approximately 90% of examined bird species show some EPFs
sexual selection
competition among individuals for access to the gametes of he opposite sex.
Monogamy costs and benefits (male)
costs: dependent on the fitness of the female, extra-pair copulating, forced parental care, only one female to inseminate/ benefits: easier to reproduce, no intraspecific competition, less pheromones to produce, high offspring survival rate
Monogamy costs and benefits (female)
costs: dependent on the fitness of the male; only one male to inseminate them/ benefits: less parental obligations; no intraspecific competition; less pheromones to produce; high offspring survival rate
Leks costs and benefits (male)
costs: energy producing visual, auditory, tactile, scent based lures for the females, competition and possible harm to the males involved, predators are easily lured to the site of the breeding ground. / benefits: if you are a more dominate male it helps you look better; if there are a lot of females waiting for a good male and you are a little less than average it helps you because at least one is likely to come to you
Polygyny costs and benefits (female)
costs: females end up taking care of the offspring the most/ benefits: territory, the chance of successful reproduction is higher
Polygynandry costs and benefits (male)
costs: group living: spread of disease, parasites, limited resources. / benefits: less time spent fighting for a mate, young are more protected, greater genetic diversity: insures that their genome is carried on
Polyandry costs and benefits (female)
costs: more energy used, female longevity decreased, there isn't much population growth as there could be, exposure to predators, exposure to aggressive males, disease. / benefits: control, more fit, more of an opportunity to find the "best" genes, maximized reproduction success
Polygynandry costs and benefits (female)
costs: more time and energy spent on multiple mates, group living: spread of parasites, diseases, limited resources. / benefits: genetic diversity
Polyandry costs and benefits (male)
costs: share offspring, don't know which (if any) offspring belong to them, chance that he won't be able to fertilize (offspring( for the female, competition, waste of time and energy if not able to produce offspring/ benefits: Results in reproduction, allows parenting to be split up between different males
precocial
covered with down and able to run or swim after birth
Precocial
covered with down and able to run or swim almost immediately after hatching
what can we do at birth? altricial
cry and have some sensory skills
cuckoo tricks
cuckoos mimic sparrowhawk parasitic species have barred breasts that startle birds presumed adaptive function is to scare potential hosts away from their nests
a minimally ritualized signal may be difficult to distinguish from a _____
cue
1. Association between a sender-produced cue and a condition
cue (i.e., production of a motor pattern, structure, sound, or chemical cue by sender) and condition become correlated
Tuning curve
curve that shows what frequencies of a particular sense are detectable to the organism
polygyny threshold model
female reproductive success increases with environmental quality
Female density is NOT correlated with lek formation in lechwe
darker=more female density=leks=female density drives leks? no. rejects hot shot hypothesis
anisogamy
difference in size of male and female gametes
material benefits. give case study examples.
e.g., Mormon crickets, red0winged blackbirds females can obtain more resources by mating with several mates more resource hypothesis: states that more mates = more resources or parental care received from the sexual partners of a female. case study: female red-winged blackbirds are helped by their male 'mistresses' -observation: females with EPFs have higher success at raising their offspring.
c) female forced monogamy. give example.
e.g., burying beetles female enforced monogamy hypothesis is similar to the mate guarded Ho, but with the female as the enforcer of monogamy in this instance
fertility insurance. give example.
e.g., drosophila, Grain beetles -polyandry reduces risk of infertile male or poor ejaculate fertility insurance hypothesis: it reduces the risk that some of the female's eggs will remain unfertilized because any one male may not have sufficient sperm to do the job.
a)mate assistance
e.g., passerine (songbirds) birds without care from father, offspring would not survive. assistance limits males ability to seek other mates
Not being able to get from there to here
evolution can be constrained ex. pandas thumb
chase-away sexual selection
evolution of a male character is neutralized by the evolution of a female character, which results in the in the evolution of an even more exaggerated male character.
Fitness
evolutionary fitness is relative: good vs great = great fair vs poor= fair fair vs good= fair fitness is an expected outcome for a genotype (different individuals with the same genotype might have different outcomes)
intersexual selection
ex. male ornaments; Selection whereby individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex; also called mate choice.
ecological constraints theory
examines dispersal options of mature offspring, and specifically the conditions that favor dispersal from home rather than remaining on a natal terrritory
reproductive skew theory
examines how reproductive opportunities are divided among potential breeders by predicting conditions that should favor conflict or cooperation over breeding decisions
Evidence in mammals that males tend to live with females when females spaced far apart on territories.
example: mate guarding monogamy in the rock haunting possum of northern Australia
intentional movements: retreat-inducing behaviors are often intentional movements
example: pulling the lips back more than necessary will reduce the likelihood of becoming engaged in a costly fight note: nonaggression or submission signals are often the opposite of threat or aggression signals (darwins principle of antithesis)
The hypothesis that SDSU seniors possess a circadian rhythm generates which of the following predictions? Students held in constant light and constant temperature in a closed room will still:
exhibit a cycle of behavioral and physiological activities of fixed duration with a period of somewhat more or less than 24 hour
sensory exploitation
exploiting one part of themselves, so that they can attract females. Like the tail on the fish, symmetry in males, pouches in frogs.
genomic studies with honeybees indicate that gene expression patterns are more strongly related to the age of the bee that the job of the bee
false
if a trait has a heritability of 1 then environmental factor f do not effect the development of the trait in that population
false
our class experiment with termites supported the hypothesis that termites use a concentration gradient to detect trial directionality
false
researches interested in systmatics and phylogenies usually aske question the ontogentic levels of analysis
false
Firefly (femme fatale) example of Deceitful communication
female fireflies (photuris) lure males of other species to their deaths by imitating the flashes given by females of their species
In rats, a ______ will display male sexual behavior in adulthood.
female injected with testosterone at birth and in adulthood
Genetic models of Female Choice
female preference doesn't change because they are so costly. Only males with good genes have the extra resources to produce and maintain them.
Who gets EPC's in blue tits?
females do not leave when intruding females are present in their territories, suggests males are attractive, and females have no incentive to leave, males with few to no intrusions=not attractive.... look at graph most blue tits generally have only one female (monogamous), few have 2 or 3 mates (polygynous) so mates with 2 or 3 females with a good territory did not suffer extra pair paternity
Female choice polygyny
females may chose a mix of genetic and behavioral mates. really evident in Lek mating systems EPC=extra-pair copulation:outside of the pair copulations EPF=extra-pair fertilization:outside sperm fertilize egg EPP=extra-pair paternity=males shown to be sire of 1 or more offspring in the nest
female help
females protest when other males try to mate with them
good genes model
females substantial loss of gene fitness if their offspring do not survive or reproduce, therefore females should evolve preference for males of high genetic quality. Then offspring will inherit these traits and have a potential fitness advantage.
Desperation hypotheses
females will chose polygyny when no other breeding options exist -polygyny only when all other territorial males are mated - secondary females have reproductive success greater that that of monogamous females in habitat of similar quality
Females come from
fertilized eggs (diploid)
What unit do biologists use when analyzing the costs and benefits of behavior?
fitness--the ability to survive and produce offspring
motivational systems within motivational conflict
hunger thirst aggression fear reproduction grooming thermoregulaion
another hypothesis argues that indirect benefits of female choice may not be about good genes for survival but about...
genes that produce "sexy sons" ex: dark mane (preferred) on lions might indicate... indicator model: "good genes"--------indicates heritable health/fitness "sexy sons"----------indicates heritable attractiveness
Two species of mice live in the same geographical region, but species 1 prefers open fields whereas species 2 lives in forests. In an experiment, when presented with simulated "fields" and "forest," individuals of each species born in a laboratory prefer the environment in which they naturally live. This experiment illustrates the concept of ______.
habitat selection
zahavi's handicap prinicple
handicap trait= a costly trait that allows only good gene males to survive for long periods of time females prefer handicaps! the handicap give females a means of judging the males genetic quality (A "good genes" model)
example of nupital gifts benefits
hanging flies -prey that male catch offer to female as gift as long as she mates with him -how large/good the food is may be indication of direct benefits
Auditory Communication
has the advantages of being fast, covers a great distance, is not affected by a visually complicated habitat but it is short lived.
Australian Fairy Wrens
have highest known rate of Extra Pair Copulation (EPC) and >75%
Haploid
have one copy of each gene
red-winged blackbirds
have ornaments such as songs and red plumage to establish dominance among males
Altruism and why it doesn't work from an evolutionary standpoint but what does and example
helpful behavior that raises the recipient's fitness while lowering the donor's direct fitness. But for example giving an alarm call in Belding Ground Squirrels does work even though it draws attention to self because you save your indirect kin so they can still pass your genes on
provide examples of genetic disorders are X linked
hemophilia, autism, red-green colour blindness and pattern balding
Eusociality is usually accompanied by
high degree of relatedness between individuals, phylogenetic history of eusociality, monogamy
Anisogamy for females
higher parental investment and/or donations-->low potential reproductive RATE-->low levels of sexual activity-->biased operational sex ratio-->selection among mates-->the better mate's quality, the higher the individual fitness
Naked mole rats (diploids) have eusociality because one queen has all the kids and everyone else takes care of them so relatedness within colonies is ____ than relatedness between colonies
higher than (very high)
what results were obtained from comparing sexual dimorphism levels (# display traits) in XY and ZW animals?
highly heteromorphic ZW species had the highest degrees of dimorphism
what do females use to assess the direct benefits from males?
honest signals or traits are used by females to access the potential of direct benefits i.e., signals or traits that may indicate whether a mate will provide material gain to female
Hyena example
hyenas always have twins and parents are pretty hands off, they are always competing for food, attention, space and in long term mates, food, territory Hyenas hate same gender siblings more
sexy son hypothesis
hypothesis that a female may increase the fitness of her male offspring by mating with a male who has especially attractive secondary sexual characteristics
Scenarios for Signal Origin fall into two categories:
i. sender preadaptations ii. receiver pre adaptations
signal origins: scenarios fall into two categories
i. sender preadaptations ii. receiver pre adaptations
hanicap
if a male has a disadvantageous trait and still survives, he must have good genes that allow him to survive (despite the trait)
How do sisters being more related than mother and daughter evolve?
if a worker were to have her own kid the inclusive fitness would be 50% if worker helps raise her sister inclusive fitness is 75% Makes more sense to help sister because more genetic information is being passed on
Mate guarding hypotheses
if female mates are hard to find male strategy may be to guard females, causing most females to be genetically monogamous
signal evolution. occurs when?
if senders benefit form response, the cue will be refined into a true signal via RITUALIZATION to maximize information transfer. ex: rifle bird and northern mocking bird
Signal evolution
if senders benefit from response, the cue will be refined into a true signal via ritualization to maximize information transfer ultimately, the signal structure evolves to enhance the benefit of sender and receiver
Hamilton's rule
if the behavior decreases the actor's direct fitness by X amount, but increases the actor's indirect fitness by >X amount, the behavior will evolve I would risk my life to save 2 of my brothers or 8 of my cousins
Mullerian mimicry
imitative similarity, typically based on warning coloration amongst a number of mimic species all of which are unpalatable or otherwise offensive to a predator
true
in Belding's ground squirrel, females are much more likely than males to emit alarm calls when predators are sighted
what new research has implied that some inactive X genes are actually expressed in the condensed heterochromatin state?
in addition to the PAR, as much as 25% of the inactive X genes may actually have some gene expression (each female has different Barr expression pattern)
traumatic insemination
in bed bugs males perforate the female's abdomen and introduces sperm directly into her body cavity (not her reproductive tract). the sperm moves through her hemolymph to reach the reproductive tract. female has 'cushion' so no permanent damage
worker policing
in honeybees sterile worker bees use info. associated with genetic relatedness to "police" their hive, and destroy eggs that are less related to them so that their inclusive fitness is increased.
What translocation of gene expression occurs on colour genes in guppies?
in less coloured relatives of the guppy, colour genes are autosomal; guppies are predominantly Y-linked for colour genes, suggesting a translocation of colour genes to the y chromosome
mate-assistance hypothesis of monogamy
in situations when resources are scarce, males may help raise offspring by bringing food to the nest and defending the offspring from potential predators. male fitness is highest when he does this
Increasing attractiveness
in some cases a male with offspring (ex. guarding eggs) is attractive to other females, shows fitness and responsibility along with prior desire from other females. thus the costs of paternal care are reduced by the fact that guarding eggs adds increased chance for matings. remember predation risks and other factors may still make care costly
sex-role reversal
in species in which males care for young, males are limited in how often they can mate, thus OSR may be female-biased and females compete for access to males.
A bee performs the waggle dance straight down on the vertical surface of the honeycomb of the hive and her waggle runs are of long duration. She is communicating to her hivemates that food is located ______.
in the direction opposite that of the sun and relatively far from the hive
true
in the superb fairy wren, male helpers often assists their parents. if a vacant territory opens up, however, male helpers are quick to leave the family unit and start their own family
Displacement behavior often appear where? give examples
in thwarting or frustrating contexts where an animal is unable to achieve an expected goal examples: -courtship displays used during threat encounters -displacement feeding during fight -displacement sleeping during fight -displacement bill-wiping during courtship
Indirect Parental Care
includes behaviors that do not have an immediate physical effect on the offspring.
Direct Parental Care
includes behaviors that have an immediate physical effect on the offspring and their survival.
Emlen's evolutionary theory of family
inclusive fitness theory ecological constraints theory reproductive skew theory
Evolution of Brood parasitism
it began with the laying of physiologically committed eggs in neighboring active nests
genetic drift
increase or decrease in genes by chance, especially in small populations • Involves differential passing down between generations ... but not as a consequence of parent individual's traits • Results in change, but not adaptation
examples of direct benefits
increased nutrition, superior territory to raise offspring, or parental care
combatting conditional mating strategies
increasing sperm by 50 percent. they are able to increase sperm because it is cheap to produce. increases chance that they will impregnate the female.
Intersexual selection
individuals between sexes choose which individuals of the other sex to take as mates.
intersexual selection
individuals of one sex (usually females) are choosy in selecting their mates from the other sex
Why has a rapid loss of Y specific genes been observed in chimps?
intense sperm competition has promoted loss of non-sperm genes, resulting in genetic hitchhiking of genes
interneurons-
involved in information processing
Interspecific brood parasites
involves a parent depositing her eggs into the nest/care of a host of another species.
Intraspecific Brood Parasitism
involves one parent depositing its eggs into the nest/care of a conspecific.
Submissive Behavior
is a behavior where an individual indicates by an act or posture that it will not challenge a dominant individual in a social group.
Reciprocal Altruism
is a behavior where an organism acts in a manner that temporarily reduces its fitness while increasing another organism's fitness, with the expectation that the other organism will act in a similar manner at a later time.
Classical polyandry
is a behavioral mating system, with sex reversal, where females have several mates who raise the offspring with little help from the female who: found in some fish and some birds
Interbrood Conflict
is a conflict between members of the current brood and future offspring.
Agonistic Fighting
is a form of aggression that escalates from an indecisive threat display.
3. Polygyny
is a more common pattern. with polygyny, males have higher variance in reproductive success
Ritualization
is a phenomenon where incipient signals become more stereotyped and unambiguous in a population over evolutionary time.
Cooperative Breeding
is a social system in which individuals contribute care to offspring that are not their own at the expense of their own reproduction.
Polyandry
is a type of polygamy where one female has exclusive mating rights with two or more males.
mating system
is a way in which a group is structured in relation to sexual behavior.
alarm signal
is an antipredator adaptation referring to various signals emitted by social animals in response to danger.
Threat Behavior
is any behavior that signifies hostility or intent to attack another animal.
Parental Investment
is any parental expenditure (time, energy etc.) that benefits one offspring at a cost to parents' ability to invest in other aspects of fitness including the wellbeing of existing offspring, parents' future reproduction, and inclusive fitness through aid to kin.
Sexual Monogamy
is defined as an exclusive sexual relationship between one female and one male based on observations of sexual interactions.
Realized Fitness
is often a a count of offspring produced
Coefficient of relatedness
is the fraction of identical genes shared between 2 individuals
Altruism
is the term for behavior by an individual that increases the fitness of another individual while decreasing the fitness of the individual performing the act.
Emancipation
is the term for the process by which a ritualized signal has become freed from the external or internal factors that originally led to it.
Aggression
is the term used by animal behaviorists for aggressive behaviors that can involve both intraspecific and interspecific behaviors.
Eusocial
is the term used for the highest level of social organization in a hierarchical classification.
Sex Allocation
is the way in which parents invest resources between male versus female offspring.
Obligate siblicide
is when a sibling almost always ends up being killed.
How does sex determination occur in Drosophila?
isn't determined by Y, but rather by number of X chromosomes: XXY = female (Klinefelter human male) XO = male (Turner human male)
Belding ground squirrels
live in big social groups, normally of family, give alarm call when see predator
solitary
living alone most of the time except for mating and parenting
social
living in groups most of the time, with relationships beyond mating and parenting
Organizational effect
long term, generally permanent developmental effect
Long-term potentiation
long-lasting enhancement in signal transmission between two neurons that results from stimulating them synchronous
investment in offspring
low in males, high in females
A nocturnal animal that to send an information-rich message that persists for a long time, doesn't require physical contact, and is not easily intercepted by predators should communicate via a(n) ______ signal.
low volatility chemical
Anisogamy for males
lower parental investment and donations->high potential reproductive rate->high levels of sexual activity->biased operation sex ratio->competition for mates->the more mates, the higher the individual's fitness
Rock, Paper, Scissors strategy
maintained by negative frequency-dependent selection. Orange is rock: Very aggressive, Large territories, Lots of females. Blue is scissors: Less aggressive, Small territories, Guard females, excludes yellow. Yellow is paper: No territories but very sneaky, sneak copulations from orange usurpers.
intersexual selection
male and female communication and interaction. in some instance, females may show preference for mates - mate choice. these preferences are often for traits that are large, more intense, or more exaggerated. these characters are often ecologically disadvantageous.
Confidence in paternity
male care is highly unlikely to evolve if the male lacks confidence of paternity. easier to determine for external fertilization.
Intrasexual selection.
male-male competition.
male-male competition
males compete with one another to attract females
resource defense polygyny
males defend resources essential to females, by monopolizing the resource they monopolize the females
intrasexual selection
males often compete against other makes either through visual displays or fighting.
tiger moths
males transfer protective alkaloids to females during mating. help protect eggs by making them toxic to potential predators. mating with males that produce more alkaloids will increase a female's fitness. males make pheromones out of their alkaloids to attract females - larger males make more pheromones, so females prefer larger males.
success with increased matings
males: yes, females: no
defensive vagina
mallard: corkscrew vagina -->male and female corkscrew in opposite directions; blocks the male penis from getting all the way-->evolved in response to intense competition such as "duck rape"
stereotypy is an important component of ___________
manakin displays
case study of good genes theory
many large eyes make for a sexy peacock -do the male ornaments signal good genes? -females prefer males with large tails and many 'eyes' offspring of males with larger eyespots show higher survival
Example of Handicap Principle.
many large eyes make for a sexy peacock -females prefer males with large tails with many 'eyes' -offspring of males with larger eyespots show higher survival
Promiscuous mating system in deer mice (Peromyscus maniculaus).
many males mate with many females. Aggregate more often with related sperm. brother sperm, from same Dad aggregate. Cousin sperm aggregate but to lesser extent.
Polyandry
many males per female sex role reversal (larger, brighter females) who: pipefish, spotted snadpiper
Polygynandry
many males per females and many females per male who: the dunnock (small bird), chichlid (fish), longspurs(birds), pipefish
Polygamy
many mates: (includes) Polygyny, Polyandry, Polygynandry
biased potential reproductive rate
many more males than females that want to reproduce. Evolution of competition traits
what is even more altricial than humans?
marsuipials
extrapair copulations
mating by a member of one sex with another outside what appears to be the stable pair bond in a supposed monogamous relationship. Eg indigo Buntings
what is the main mating system of humans?
mating system of humans is AKA Marriage
Broadside threat display
may represent blending between fear (turn and run) and aggression (face to fight) -display often involves an exaggeration of size
Anisogamy and its consequences
means (different sized gametes,egg/sperm) Trivers states, because male gametes are smaller they will tend to invest less in care and more in seeking mating opportunities
Fitness
measure of the genes contributed to the next generation; stated in terms of number of offspring that survive to reproduce
University of St. Andrews researchers created composite images of women with high levels of estrogen, and low estrogen levels. Men were asked to rate which one was more attractive. what did they find?
men rated women with higher levels of E as more attractive, healthier and more feminine-looking than those with lower levels
ritualization of displacement preening during courtship in various ducks
mock preening by courting male ducks during courtship is thought to have evolved from displacement preening -movements emphasize bright markings on wings displacement behavior= acts that are apparently irrelevant and out of context in which they appear and are often interspersed between relevant acts (Tinbergen 1952) Shelduck-- displacement preening occurs during conflict situations but is similar to normal preening and therefore relatively UNRITUALIZED. Mallard-- preening is partially unritualized; preening movement are restricted in range and directed at a patch of conspicuously colored feathers on the wing Garganey-- more ritualized preening; with incomplete movements that no longer serve any grooming function but are directed toward a light blue patch Mandarin--highly ritualized preening; bill merely touches an enlarged conspicuous rust-red feather that becomes erect during courtship; the crest on back of head further emphasized the preening movement.
Reproductive Value Model
models the tradeoffs between reproduction, growth, and survivorship.
sexually receptive
more often, less often
what type of adaptive sex ratio bias occurs in parasitoid wasps?
mothers adjust the sex of their egg based on size of their host (favour female eggs in bigger larvae because females benefit most from being large in this species)
Kinesis
movement or cell activity in response to a stimulus
visual signals consist of
movements, postures, and physiological processes with visible external effects
iteroparous
multiple reproductive episodes before death
Altricial
naked and helpless at hatching
altricial
naked and helpless at hatching
kamikaze sperm hypothesis
natural selection might favor the production of some sperm types that are designed to kill other males' sperm rather than fertilize eggs
Altricial Definition
need mom when born; born blind and without hair
With multiple fathers eusociality doesn't work because
need monogamy
what are neo-Y chromosomes and why are they useful in testing theories?
neo-Y chromosomes are male restricted, and subject to the same evolutionary factors that cause degeneration of y chromosomes; commonly used in Drosophila to study y chromosome degeneration
Are all activities correlated with environmental cycles the result of biological clocks?
no
If a bird is trained to seek food on the western side of a cage open to the sky, and is then placed in a chamber with a controlled light cycle so that its circadian rhythm becomes phase-delayed by hours, when it is returned to the open cage at noon in real time, it will seek food in the ______.
north
Does evolution lead to optimal outcomes?
not necessarily. its suffices may not be the "best" but will be "good enough" once a plan is underway it may be difficult to change ex. querty keyboard and DNA code
interneurons
nuerons involved in information processing
resource defense
occurs when males defend resources that attractive females want
mate defense
occurs when males fight with other males to monopolize groups of females
Scramble competition
occurs when males skip territoriality and/or combat instead rush to outrace their rivals to mate with receptive females
sperm competition
occurs when the sperm of two or more males have opportunity to fertilize a female's eggs. In some cases, males sire more offspring if they produce more sperm or they may have evolved traits to eliminate the competition.
Waggle dance
of the honeybee involves figure eight patterns of movement.
vegetative propagation
offspring arise from a group of cells
parthenogensis
offspring develops from a single cell (clones)
dynasty building hypothesis
offspring from families that control high-quality resources are likely to be much more reluctant to vacate the natal territory, as few alternative territories provide the resources that are available at home
receiver-bias models of signal evolution rely on what concept?
on the concept of feature detectors Feature detectors= neurons that are selectively responsive to specific features of a sensory stimulus
Polyandry
one female with many males -more nutrients and food provided, more parental assistance from several mates, etc.
Polygyny and example
one male mates with two or more females. Example: ....
visual signals evolve from what?
three types of sender sources: 1. intentional movements 2. motivational conflict 3. Autonomic processes
Monogamy
one mate per female, one mate per male who: some fish, predominates in altricial birds, rare ing mammals because of female lactation (tends to make monogamy rare). mates may shuffle between years (especially in migratory species, but that is even rarer)
exclusive rewards (of mutualists)
only pseudomyrmex can access Acacia's resources
PAR (pseudoautosomal region)
only regions on the X or Y chromosomes that allow genetic recombination
You train your pet dog to "sit" and "roll over" on command by rewarding it with a dog biscuit whenever it performs the desired behavior. This is an example ______.
operant conditioning
Avoiding being eaten is typically a compromise for animals. If a frog remains silent, then he can't attract mates. Inability to attract mates is a(n) ______ cost of remaining silent for the male frog.
opportunity
Birds spend some of their time scanning the horizon for predators. While scanning, they cannot be foraging for food. This situation illustrates the phenomenon of ______.
opportunity cost
secondary sexual traits in males
ornamental plumage bright colors courtship displays
scientist who study birds
ornithologists
Challenge Hypothesis
outlines the dynamic relationship between plasma testosterone levels and aggression in mating contexts in many species.
Post-copulatory selection strategies most commonly seen in what mating system?
polyandrous mating systems:
genetically compatible sperm. give example study.
polyandry increases the likelihood of mating with a male whose genotype is a good match to genotype of female's egg prediction: embryos have higher survival genetic compatibility hypothesis--mating with several males increase the genetic variety of the sperm and chance that some sperm will have DNA that is an especially good match with the DNA of her eggs. case study: egg hatching success in field crickets is related to number of mates. but no one male had more 'infertile sperm'
Sexual dimorphism in body size, with males larger than females, should be most pronounced in ______ species and least pronounced in ______ species.
polygynous; monogamous
Song Crystallization
practice generates a large repertoire of songs -last part the young bird chooses a song that matches a memorized tutor's song -this becomes his main vocalization during life
Guinea Pigs
precocial
the difference between altricial and precocial young
precocial: ready to go as soon as they hatch altricial: need food brought to them and protection from predators
When large prey are abundant, the bluegill sunfish ______.
preferentially eats large prey
A student wishes to repeat Pavlov's protocol for the conditioned reflex using a puff of air to the cornea of the eye as the unconditioned stimulus and blinking as the unconditioned response. The conditioned stimulus will be a tone, and the conditioned response will be an eye blink to the tone. The student would ______.
present the tone immediately followed by the puff of air
4. Association between updated information and the development of a receiver decision rule
previous experience influence decision rules
Social Grooming
primates grooming is often used to maintain social bonds.
P-Value
probability of obtaining a test statistic that is as extreme or close to the one that was actually observed
procedure and results for cricket study
procedure: 1. feed spermatophyllax to female gryllodes. other females not allowed to feed on spermato. 2. feed spermatophyllax to female acheta cricket (non nuptial gift giving species) other females not fed. 3. measure time until female mated. results: 1. spermatophyllax delayed female acheta remating-anti-aphrodisiac quality (assumed) 2. spermatophyllax did NOT delay remating in Gryllodes females -assumed resistance to effect evolved.
Sexual reproduction:
process that creates new offspring by combining the genetic material from the fusion of gametes (sperm & egg) from two individuals.
asexual reproduction:
process that creates new offspring from a single parent, and inherit the genes of that parent only. Does not involve meiosis. Does not involve ploidy reduction. Does not involve fertilization.
polygynandry
promiscuous breeding system. several males form pair bonds with several females simultaneously
when mates are not limiting
promoted behavior is choosiness and little competition for mates-->everyone gets what they want
Sex change:protandry and protogyny
protandry:payoff to being female may increase with size (large females more fecund) ex.hermaphroditic gastropod becomes more female as it grows larger, several fish species, NO birds or mammals protogyny:large individuals can control access to others and become the only male breeders in a group (largest female in group will switch sex when no male mate in group and become the male breeder) ex. number of fish particularly reef fish, no birds or mammals
mechanisms to increase mating success in sperm competition success
proteins in ejaculates, genitalia morphology, number and speed of sperm
Females only come from kid of
queen and drones
Coefficient of Relatedness
r in Hamilton's Rule. A measure of how closely the actor and the beneficiary are related. Measures the fraction of alleles in the actor and beneficiary that are identical by decent (inherited by the same ancestor). Ranges from no relation to identical twins (0-1.0)
Central pattern generation
r- neural circuits that when activated can produce rhythmic motor patterns such as walking, breathing, flying, and swimming in the absence of sensory or descending inputs that carry specific timing information (preprogrammed set of messages?)
operational sex ratio
ratio of reproductively available males and females; the sex that invests the most is assumed to be less available for further reproduction (basis of Bateman's principles)
operational sex ratio
relative number of males and females in the mating pool a nay given time. Females are constrained by the and energy and cannot mate very frequently during a breeding season. little energy constraints on males.
1. access to food
results: males were more tolerant of neighbor females feeding on their territory if they had copulated with her. so... females gain food resources!
redirected behaviors can become _______
ritualized
Homing
round trip movements to a fixed goal or moving to a known location, requires compass and odometer
Fixed action patterns
s-an instinctive behavioral sequence
Does Familiarity also apply to attractiveness?
see mona lisa example on slides--one of the images is the original and the other is mirror reversed... people prefer the original. -people like faces and other images they have seen before--familiarity. -This effect may be responsible for popular beliefs that partners look alike or that partners are selected to look like our parents. -both our own and our parents faces are very familiar and we may be attracted to individuals whose faces resemble our own or our parents.
Provide evidence of how sexual selection acts on the individual as opposed to the group
selection acts on the individual and its selfish genes by favouring the rarer sex in an uneven sex ratio
What did R.A. Fisher propose about how sexual selection acts?
selection acts on the individual, not the group
How does sexual selection work in relation to uneven sex ratios?
selection pushes the sex ratio back to 1:1 whenever one sex becomes more common by favouring the rare sex
indicator traits
selection would favor females with a genetic predisposition to prefer traits correlated with good genes
Deceit (manipulation)
sender benefits form the provision of information but receiver does not! ex: a deceptive signaler= orange anglerfish with lure
sensory drive is compatible with what view?
sensory drive is compatible with the transitional view of signal evolution previously outlined but emphasized the importance of receiver filtering at link 2, receiver tuning an ritualization
Umwelt
sensory world of animals (what an animal can and can't see,smell, feel, etc.)
secondary sex ratio
sex ratio at birth, which can be modified by differential survival of males and females, selective abortion, cytoplasmic pathogens, etc.
tertiary sex ratio
sex ratio at reproductive maturity, which can be modified by differences in survival btw sexes
primary sex ratio
sex ratio of zygotes (fertilized eggs) produced
isogamy:
sexual fusion of gametes of similar size and form.
why is territoriality important to the survival of birds
to provide enough feeding area for birds of specialized diets
good reasons for being social
sharing food, information group defense of resources modification of environment division of labor cooperative brood care
2. Perception of the cue by the receiver
signal is perceived against background by receiver
direct benefits: parental effort or ability healthy good forager birds do what?
signal or trait may indicate male parental effort healthy good foragers... -may produce better signals -foraging ability is benefit in caring for young -females prefer males with larger song repertoires -males with larger reps are better providers for chicks
the general categories of deceitful signals
signaler can: 1. emit false signal -bluff or exaggerate 2. withhold a signal (such as a signal that indicates alarm or food location) 3. ignore (spite)
Sender preadaptations: finding precursors--Identifying the precursors (sources) of current signals. How would you identify the sources of the signals?
signals and responses often don't leave fossils, so how can we learn about evolutionary history from living species? The Comparative approach: -create a phylogeny (typically using molecular data) -map signals/responses onto the phylogeny -reconstruct trait evolution and ancestor state using parsimony -Parsimony= the simplest scenario (with the fewest number of evolutionary changes) is more likely to be correct
runaway vs. chase-away models
similarities: -both lead to process of exaggeration of male trait differences: 1. runway model--leads to increased female preference for trait 2. chase-away model--leads to decreased female preference for trait 3. chase away model--female preference for trait results in negative fitness effects for her (via sensory exploitation) 4. female/male cooperation vs. female/male conflict
satellites
slip in and mate every once in a while b/c they are smaller
male gametes
small, abundant, and cheap (in terms of energy investment) -ex. males: 300-500 million per ejaculation
why do most birds of temperate regions migrate to the tropics for the winter
so they're in a warmer region than where they were before migrating
good genes
sometimes called indirect benefit models
monogamy is a rather rare first thought. is dual monogamy a myth? give an example
song birds old view: most song birds monogamous--->modular techniques--->modern view: monogamous species are rare
Use of Parsimony to Find Precursors example
song repertoire and song complexity in Emberizine Sparrows (Irwin 1988) there is a large diversity in song repertoire size and complexity in emberizine sparrows did complex repertoires evolve from simple, or vice versa? *it is more parsimonious to assume that the ancestor was complex, and that simplicity evolved once in Zonotrichia. (see phylogeny tree in slides with where changes could have occurred)
Adaptationist Hypothesis
song sparrows that produce distictive, species-specific songs are more likely to attract mates than ones that produce less distinctive songs
A female rate will show female sexual behavior in adulthood if it is ______.
spayed as a newborn and given estrogen injections as an adult
example of chase-away evolution
sperm and egg. sperm compete for eggs, so there is selection for the evolution of the speed of fertilization. faster sperm = higher male fitness. eggs have evolved elaborate ways to slow down the sperm and sperm have evolved ways to speed up.
benefits of being polyandrous
sperm replenishment material benefits genetic benefits convenience
mate assistance hypothesis. give examples
states that males remain with a female because parental care and protection of offspring are especially advantageous ex: male seahorse nurtures and carries and gives birth ex: paternal male starlings keep their clutches warmer
example of good genes theory
strong immune response correlated with song rate in male starlings
use the peacock example to explain when the survival value of the trait is no longer valuable.
tail length only reaches an equilibrium length when the survival value of the trait is so poor that increased mating success cannot compensate. in the end, the trait has overshot its "survival optimum" during its elaboration.
sperm replacement
taking out one males sperm and replaces it with its own.
How was the origin of the Lemba tribe argued based on mitochondrial DNA?
the Lemba tribe claim a jewish origin; Y chromosomes show semitic patterns in over 50% of Y chromosomes, but mitochondrial DNA shows no jewish origin
fitness
the ability of an individual to pass on its genetic contribution to future generations.
competition
the active demand for a limiting resource shared by two or more individuals or species.
Batesian mimicry
the close resemblance of a palatable or harmless species to an unpalatable toxic species in order to deceive a predator
fitness cost
the damaging effects of the trait on measures of individual reproductive success
what did the Trivers-Willard hypothesis demonstrate in the study of red deer?
tolerance of high blood glucose in male embryos provided evidence of the trivers-willard hypothesis (mothers produced more sons because they were able to transport more blood glucose due to higher abundance of resources)
Action potential-
the electrical signal that is sent from one nerve cell into the next to send a message to the CNS or to the body
runaway sexual selection
the evolution of a male trait and a female preference, once initiated, becomes a self-reinforcing positive feedback loop
Biased Operational sex ratios
the fact that there are typically many fewer sexually active females than males at any given time because females that have already mated often have nothing to gain by copulating again (male-biased ratio)
Direct fitness
the genes contributed to the next generation by an individual via personal reproduction in the bodies of own offspring
what might, in part, explain the attractiveness of averageness?
the genetic compatibility hypothesis
Some birds give a species-specific vocalization called an "alarm call" when they see a predator, although this call may direct the predator toward them. Other members of this species respond to these calls by taking cover. This would be an example of altruistic behavior that is beneficial to the calling bird if ______.
the inclusive fitness of the bird giving the vocalization is increased
What do conspecific females who differ in their fecundity differ in?
the number of offspring they produce who survive to successfully reproduce themselves.
Hamiltons Equation (r,b,c)
the relatedness coefficient ( r ) range=0-1 0=no genes from a common ancestor 1=all genes from a common ancestor siblings=.5...half genes shared cousins=.125 ...eighth genes shared
anisogmy
uneven parental investment in energy allocation toward gametes results in a conflict of interest between the sexes. females invest a lot more energy per gamete than males. If a male choose a poor mate, he is not penalized fore a bad "investment" of energy. Females however, are heavily penalized.
both queens and workers can lay ____ to make drones
unfertilized eggs
Males come from
unfertilized eggs (haploid)
instinct
unlearned knowledge an animal possesses from birth
A (true) communication system will not evolve initially unless what?
unless it raises fitness of both sender and receiver. *once established, signals can be exploited.
altruism
unselfish concern for the welfare of others; selflessness
entertainment
using environmental cues to regulate circadian rhythm
nupital gift
usually a food item bestowed to a female as a part of the courtship
syrinx
voice box
armaments
weapons used in combat
Indirect Inclusive fitness
what you do to increase other kins number of offspring (just because you are kin doesn't mean you will get along)
mate choice copying
when a female's mate choice preference is affected by the preference of other females in her population
Siblicide
when benefit of being one offspring is enormous hyenas kill same gender twin 50% of the time
interspecific competition
when individuals of different species affect the growth and reproduction of each other by sharing limited resources.
intraspecific competition
when individuals within the same species affect the growth and reproduction of other members of that species by sharing limited resources.
scramble competition
when intraspecific competition depletes a resource and it affects all members of a species equally.
contest competition
when intraspecific competition depletes a resource and it affects some members of species more than others.
Lek
when males fight to control small display area to attract females (ex: those birds...)
How does sexual selection exhibit negative frequency dependence?
when one sex becomes more common, the rarer sex becomes more valuable
promiscuity mating system
when polyandry and polygyny are occurring in the same population of animals
albumen
when the egg expands
antagonistic coevolution
when the genes that govern male and female traits conflict it can lead to an evolutionary armsrace between males and females
sexual dimorphism
when the male and female look different and are different sizes.. and act differently
Ultimate
within a population/species -about function -includes breeding values - getting mates and making babies with good chances of surviving and reproducing, i.e., its current utility. -about evolution -history: what is the legacy of descent with modification of a behavioral trait - what was the traits utility in the past?
Ultimate type 2
within a population/species -about function (level 3) -includes breeding values - getting mates and making babies with good chances of surviving and reproducing, i.e., its current utility. -about evolution (level 4)-history: what is the legacy of descent with modification of a behavioral trait - what was the traits utility in the past?
cuckoldry
women cheating on the male
why are most x-linked diseases more common in men than women?
women have a second X chromosome (expressed as a genetic mosaic)
3 kinds of bees are
worker (female, diploid), queen (female, diploid), and drone (male, haploid)
Drones and queens make
workers
do species vary with respect to how many mates males and females have?
yes.
is polygyny costly towards females?
yes... assumed by the polygyny threshold. males did not care for young of secondary females
Hymenoptera
you are more related to your sisters than your own kids
Haplodiploidy
you have both haploid and diploid within species
Direct Inclusive fitness
you having offspring
From your perspective if mom has 3 kids with another dad you want all the resources because
you're not related to the other children
Number of asexual vertebrates.
~0.17%. 22 species of fish, 23 species of amphibians, 29 species of reptiles.
First 4 theories
~Family groupings will be unstable, disintegrating when acceptable reproductive opportunities materialize elsewhere ~Family stability will be greatest in those groups controlling high-quality resources. Dynasties may form. ~Help with rearing offspring should be the norm ~Help will be expressed to the greatest extent between closest genetic relatives
Paternity Uncertainty and Parental Care in Boobies Results
• Almost half of males in the experimental condition removed the first egg laid by the female from the nest, subjecting it to predators • No control males removed any eggs
Hatch Asyncrhony and Brood Reduction in Blackbirds (Forbes et al. 2002) Methods
• Checked nests daily. Uniquely marked eggs and resulting chicks with nontoxic coloured markers. • The first two chicks hatched in a nest were marked as core and the others as marginal. • Weighed nestlings each day and noted mortality until chicks were twelve days old.
Hatch Asyncrhony and Brood Reduction in Blackbirds (Forbes et al. 2002) Results
• Core chicks were heavier than marginal ones in each year of the study • Nestling survival was highest for core nestlings and significantly lower for marginal offspring.
Egg Guarding and Opportunity Costs of Parental Care in Frogs Results
• Daily egg mortality was negatively correlated with attendance • Males were more likely to attend larger clutches
Paternity Uncertainty and Male-Only Care in Sunfish (Neff 2003) Methods
• Divided territorial bluegill sunfish males into two groups on the day of spawning. Treatment: four sneaker males placed in clear plastic containers near the nest. Control: empty plastic containers placed near the nest. • Placed an egg predator (a pumpkinseed sunfish) in a clear plastic container near each nest the next day for two 30 second periods to simulate a threat to the eggs • Recorded the amount of defense behaviour exhibited by each male to the predator (lateral displays, opercular flares, and bites)
Why do parents sometimes produce more offspring than they can care for?
• Extra offspring provide some insurance (if the first born dies, a second can live) • Parents do not have information on future food availability
• Using examples, distinguish between the various forms of polygyny, and discuss under which conditions each might be favorable.
• Female defense- females clumped • Resource defense- resources clumped • Lek- females/ resources distributed • Each topi male in a central position at his lek mates with more females per capita than do amles forced to peripheral sites • Scramble competition- females/resources distributed, small window of oppurtunity
• Using examples from your text, discuss 5 hypotheses (4 about material benefits, 3 genetic) as to why a female might mate with more than one male (polyandry).
• Genetic benefits= • Fertility insurance • good genes • genetic compatibility • Material benefits= • more resources • better protection
Prolactin and Incubation in Penguins (Massaro et al. 2007) Methods
• Group 1: Sampled before an artificial egg was added to the nest • Group 2: Sampled three to four days after artificial egg added to their nest (visual and tactile cues) or next to the nest (visual cues only) • Group 3: Sampled at the same time as Group 2, but no egg was added to their nest (control)
• High fecundity produces _______ _______ offspring with ______ parental care and survivorship (e.g. ________) • Low fecundity produces _______ _______ offspring with ______ parental care and survivorship (e.g. ________)
• High fecundity produces many small offspring with low parental care and survivorship (e.g. fruitflies) • Low fecundity produces few large offspring with high parental care and survivorship (e.g. elephants)
Prolactin and Maternal Care in Rats (Bridges et al. 1990) Subsequent study results
• In the absence of priming with progesterone and estradiol, females did not display maternal behaviour • Females with nonfunctional prolactin receptors will exhibit very low levels of maternal care behaviour
Why are female costs higher than male costs in these situations?
• Larger females can produce more eggs, but this requires a higher energy input. • External fertilization increases paternity assurance, decreasing male costs.
Egg Guarding and Opportunity Costs of Parental Care in Frogs Methods
• Males attending eggs were captured and uniquely marked • Male egg attendance behaviour was monitored • Egg mortality was determined by counting eggs in the nest
Conspecific Brood Parasitism in Ducks (Ahlund & Andersson 2001) Results
• Nesting parasites had higher reproductive success than pure parasites and non-parasites. • Pure parasites had the lowest reproductive success.
Prolactin and Incubation in Penguins (Massaro et al. 2007) Results
• Only visual stimulation: no difference in prolactin levels, incubation behaviour, or brood patch development • Egg in nest: higher prolactin, wider brood patch, more time spent incubating
Predation Risk and Parental Care in Golden Egg Bugs Methods
• Placed four adult males in an aviary with two bird predators • Two males carried eggs on their backs (parental care); two males did not carry eggs • Recorded the last bug alive in the aviary
Brood Reduction in Fur Seals (Trillmich & Wolf 2008) Results
• Single pups have high survivorship • Pups with siblings have very high survivorship when food is extremely abundant • Pups with older siblings have high survivorship when food is abundant • Pups with older siblings have low survivorship when food is scarce
Life History Variation in Fish (Vila-Gispert et al. 2002) Results
• Species with larger body size tended to have higher fecundity, larger maturation, and fewer reproductive events per year. • Species with more parental care tended to have larger eggs.
Brood Reduction in Fur Seals (Trillmich & Wolf 2008) Methods
• Studied tagged wild females for ten years • Unweaned older pups were marked with ear tags and younger siblings with dye • Survivorship was noted for first 30 days • Food availability was estimated using sea surface temperature measurements
Predation Risk and Parental Care in Golden Egg Bugs Subsequent experiment results
• The sexual selection hypothesis does not apply to egg carrying behaviour because females do not prefer males who carry eggs. • Consistent with the natural selection hypothesis, egg carrying by males is favoured when lack of care leads to very low offspring survival (e.g. areas with high parasite predation on eggs)
Juvenile Hormones and Parental Care in Earwigs (Rankin et al. 1995) Methods
• Topically added juvenile hormones in acetone to females on the day of oviposition to keep levels artificially high • Controls: either did not manipulate hormones or topically added only acetone
