B1114 MT2

Feeding Specializations

Extreme skull flexibility Teeth that curve backwards Extreme stomach acids Infrequent feeding

Zahavi's handicap hypothesis

"An individual with a well developed sexually selected character [such as a peacock's flashy tail] is an individual which has survived a test. A female which could discriminate between a male possessing a sexually selected character, from one without it, can discriminate between a male which has passed a test and one which has not been tested. Females which selected males with the most developed characters can be sure that they have selected from among the best genotypes of the male population. "

Drift, Mutation, and Genetic Diversity

- Drift tends to reduce heterozygosity - Mutation increases heterozygosity - Genetic polymorphism thus a function of rate of drift and rate of mutation (Selection may act before, during, or after, in concert with or in opposition to these forces)

Mutation Meltdown

- Over time in asexual populations, the proportion of low fitness individuals with many deleterious alleles increases

More Variability

- Sex facilitates the generation of novel combinations of alleles more readily than mutation alone. (Produces what's never been seen, completely new and unique) - Sex disrupts linkage disequilibrium through crossing over and thus facilitates novel allele combinations more than mutation alone. - Variability hypotheses are associated with variable or fluctuating environments.

Fewer Lethals

- Sex may help to hide or purge deleterious alleles (or even those that just have low fitness) from the general population (asexual reproduction can't get rid of mutations and mistakes and most mutations tend to be negative) - Muller's ratchet: Deleterious alleles will accumulate in an asexual population over time if mutations from "bad" back to "good" or "neutral" are rare. The number of individuals with 0 low-fitness mutations will decrease from generation to generation as mutation load increases. (Accumulation of these alleles cause a decrease in population size

Migration (Gene Flow)

- The movement of some individuals of a species from one population to another - Introducing of removing alleles from the population - Migration can maintain genetic diversity in the face of natural selection or genetic drift (violates Hardy-Weinberg) - Simply the moving of genes across or between populations (Here it's random, not always, but in this class, it should be thought of as random)

Adaptations

-(Noun) Specialized features that enhance fitness (adaptation, natural selection, nonrandom events, and fitness all go together) -(Verb) The process by which features that enhance fitness are fixed in a population - A trait that increases the fitness of an individual ina particular environment (like darwins finches) - When a population changes in response to natural selection

Causation Problems

-Differential reproductive success and survival are the effect of differences in fitness -Linkage among traits (pleiotropy) and passage of time, it can be complicated to evaluate WHAT selection has selected FOR (and thus it can be hard to determine whether something is an adaptation)

Mate Attraction or Competition

-Females who choose their mates generally cause that males to have elaborate or different traits. (Like peacock tails, females tend to go for the more elaborate patterns so peacock tails in the mails are just that). -When male competition occurs you can get things like antlers (both defense or offense). - For plants to pollinate, like one of the largest flowers in the world has a scent of rotten flesh because flies typically are attracted to this and will then pollinate the plant.

Adaptaions MUST

-Improve fitness such that organisms WITH the trait have higher fitness than those without. (Like Finches and beak size, the version with the large beak improved fitness, those with larger beaks had greater fitness than those with smaller beaks). -Show correlation between the presence of the feature and the hypothesized selection pressure. -Does it enhance fitness? (correlation does not equal causation, is there a correlation between the beak and the selective pressure) Does it presence correspond to a specific selective regimen?

Adaptions often most apparent from comparisons of related species specialized for different niches

-Modified beak for fish and kill -Insulated by a thick layer of fat to retain heat -Webbed feet for paddling -Small, dense feathers for insulation and waterproofing -Modifies circulatory system to retain and distribute heat -Wings form powerful flippers for swimming (not capable of flight)

Analogous Structure

-structure that has the same function but different construction and was not inherited from a common ancestor - Product of convergent evolution - Independent evolutionary origins... the same type of adaptation can evolve more than once - (Octupus eye and vertebrate eye have the same functions but were not due to common ancestry. Or, the bat wing (mammals) and the bird wing (reptiles), they both independently evolved wings, convergent evolution.

Effects of Adaptation

1) Decrease in firing rate of the adapted neuron 2) Decrease in sensitivity when the adapting stimulus is immediately presented again

1. In a population of organisms, some develop small teeth that make it harder to crush seeds and nuts. Is this an adaptation? 2. What if that same population was in an environment where they ate only berries and other soft foods?

1. No 2. Yes

Limits to BSC (extinct species)

1. if interbreeding is that key, we can't figure out extinct species! 2. we can't determine if geographically separated systems can interbreed or not

Observations that led to BSC

1. variations between species (genetic differences) 2. geographic variation b/t populations (look different in different regions, but interbreed where populations meet, forming hybrids) 3. sibling 'cryptic' species (reproductively these are different species, but they look alike).

Genetic Drift

A change in the allele frequency of a population as a result of chance events rather than natural selection. (Population-level) - Cannot lead to a population being better adapted to the environment. Adapted means fitness and genetic drift is random and has nothing to do with fitness. Cannot associate adaptation (fitness, natural selection) with random events. -View a family (small population), suppose they have 3 daughters (with a 50:50 ratio determined) but this family had all of one sex but it's not odd because it's a small sample size however it'd be weird if they had 30 children and all were female. - The larger the population the less likely genetic drift happens

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.

Crypsis

A defense against predators in which prey species have a shape or coloration that provides camouflage and allows them to avoid detection.

Intrasexual Selection

A direct competition among individuals of one sex (usually the males in vertebrates) for mates of the opposite sex. Within members of one sex, male-male competition, female-female.

Sexual Selection

A form of natural selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates. Mate Choice: Female/Male Choice of whom to mate with Contests: Male-Male fights/Sexual coercion Sperm Competition: Females mating with multiple males - Opportunites depend on life history (organisms that do not encounter their mate they cannot directly select for certain features, no choice). - Organisms that mate with one partner cannot select gametes (no sperm competition) - Violates Hardy-Weinberg random mating principle. Random mating does not occur when you select your mate and no natural selection (all offspring have an equal chance of survival and reproduction) is also violated.

Species

A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. (The outcome of reproductive isolation). - Populations linked by history - Characterized by shared, derived attributes - Genetic and morphological continuity maintained by interbreeding

Molecular Species Concept

A group of organisms are classified in the same species if they appear identical in DNA sequences

Solenobiella

A population cluster that is diagnosable by a unique combination of features. - All populations of solenobiella share a common characteristic.

Convergent Evolution

A process by which unrelated organisms independently evolve similarities when adapting to similar environments. (North American Cacti and African Euphorbia, both deserts species and look extremely similar but are both more closely to other plant groups but because of their environment they look closely related) (In cave-dwelling animals loss of sight, so on)

Prezygotic Barriers

A reproductive barrier that impedes mating between species or hinders fertilization if interspecific mating is attempted. (Prevents it decreases the frequency or incidence of mating) Positive Assortative Mating: Non-random mating based on genotype or phenotype (like mates with like)

fitness landscape

A significant shift in the phenotype might push organism "off and over" the adaptive peak Visualizing the relationship between genotypes and reproductive success.

Vestigial Structures

A structure that is present in an organism but no longer serves its original purpose

Which of the following statements describe a "greenbeard" allele? 1. An altruistic allele discovered by Richard Dawkins causes cells to form green fruiting bodies ("beards") in Dictyostelium slime molds. 2. An allele that causes the development of a trait, recognition of the trait in others, and altruistic behavior toward others that carry the trait. 3. An allele that causes the development of a trait, recognition of the trait in others, and encourages the evolution (at other loci) of altruistic behavior. 4. A theoretical evolutionary mechanism that could drive an allele for altruism to a high frequency without the involvement of organism-level kin selection or reciprocal altruism. 5. A theoretical evolutionary mechanism proposed by Richard Dawkins may occur in slime molds.

A theoretical evolutionary mechanism proposed by Richard Dawkins may occur in slime molds. - An allele that causes the development of a trait, recognition of the trait in others, and altruistic behavior toward others that carry the trait. - A theoretical evolutionary mechanism that could drive an allele for altruism to a high frequency without the involvement of organism-level kin selection or reciprocal altruism. - Richard Dawkins proposed this concept long before the Dictyostelium slime mold example was discovered. The "greenbeard" name comes not from the slime molds, but from Dawkins' original, hypothetical, example of an allele that causes the growth of green beards in men.

Wings evolved independently in bats and birds and thus are not due to sharing common ancestry. The wings of a bat and the wings of a bird are and show morphological _.

Analogous, convergence. Similar traits, morphological convergence meaning they're not due to common ancestry.

The graphs plot the benefit/cost ratio vs. time for nursing in mammals. Correctly match each label on the graph with its meaning/interpretation. https://wps.pearsoned.com/wps/media/objects/15335/15703573/img/12_q16_parents.jpg a. Beyond this time, maternal fitness is best served by weaning the offspring. b. This is the optimal weaning time of an offspring sharing maternal care with a group of half-sibs. c. This is the optimal weaning time for an offspring sharing maternal care with a group of full siblings.

A. Point * Remember that the time of weaning conflict is the difference in optimal weaning time perceived by the parent vs. the offspring. B. Point ‡ Remember that differences in optimal weaning time are a function of the parent's relationship to its offspring and the offspring's relationship to itself vs. the other recipients of its mother's milk. The more equal the relationships, the earlier the optimal weaning time. C. Point † Remember that offspring devalue parental care relative to the parents.

Adaptations should be the result of natural selection and natural selection is the only known explanation for adaptation. True/False

Adaptations should be and are the result of natural selection and it is also the only known explanation. So, both are true. (Even for a random mutation were to occur and it proved to be beneficial (high fitness) selection has to occur to decide whether it's beneficial or not. As soon as fitness comes into play your discussing natural selection.)

If genetic drift is the only microevolutionary force acting on a population, what are the eventual frequencies of alleles in the population?

All alleles except one will always be lost from the population - With population size, all you change is how long it will take (speed) but not whether or not it will occur so eventually at there will be only one allele and all the others will be lost. - So, it does not depend on the size of the population here because it says drift is the only source, no natural selection, and all other ways evolutionary occurs. Only drift is occurring but the frequencies have to happen eventually (Random in regards to changes in fitness, not affecting fitness at all).

Trade-offs

Alternatives that must be given up when one is chosen rather than another -Adaptations for one function may compromise another function (few large eggs or lots of small eggs, more offspring with poor offspring survival, or fewer offspring with higher offspring survival, which is better? Depends on the species)

Haploid

An organism or cell having only one complete set of chromosomes.

Asexual to Sexual Reproduction

Asexual reproduction is the process by which offspring are produced from a single parent; does not involve the joining of gametes and sexual reproduction is reproduction using the joining of gametes from two parents. - Most sexually reproducing lineage (separate individuals) have a sex ratio of 50/50. - Females determine the reproductive output. (Females produce the largest gamete, egg, so females determine the reproductive output, the more females the more offspring.

Difference between genetic diversity and genetic variation?

Both at population level but genetic variation can be minimally discussed within individuals.

Morphological Species Concept (MSC)

Characterizes a species by body shape and other structural features - Fails in many cases but also works well

Phylogenetic Species Concept (PSC)

Defines a species as the smallest group of individuals that share a common ancestor - If things cluster together in a group on a tree then they're the same species. - Most popular species concept

Biological Species Concept (BSC)

Definition of a species as a population or group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring, but are not able to produce viable, fertile offspring with members of other populations. (If you can reproduce then you're a species, but if you can't then you're not the same species. This isn't correct because of things like the mule). -This concept has many flaws because in theory it makes sense but isn't necessarily true. -Species are populations of variable individuals connected through gene flow.

Zahavi's Handicap Principle

Displaying a noticeable handicap to survival that actually indicates survival strength - Females here are picky - Males here have extreme morphologies in comparison to females (which comes at some form of cost, energy required, appear more noticeable to predators, etc.) For instance fish with really long brightly colored fins, it makes them slower and takes a lot of energy to maintain/grow. - Males differ in terms of the expression of the extreme morphology. - They face greater threat, but despite the handicap they have greater fitness.

Examples of adaptations

Elephant's trunk, turtle's shell, camouflage, mimicry

Game Theory

Evaluates alternate strategies when outcome depends not only on each individual's strategy but also that of others.

Isolating Mechanisms

Features of behaviors, morphology, or genetics which serve to prevent mating or breeding between two different species (e.g., temporal isolation, in which individuals are active at different times of the day, seasons, or mating periods; ecological isolation, in which individuals only mate in their specific habitat; behavioral isolation, when there are no sexual cues between representatives of the species; mechanical isolation, when there is no sperm transfer during an attempted mating; and gametic incompatibility, when there is sperm transfer without fertilization occurring). If mating can take place, there are four factors that prevent hybrid viability: zygotic mortality (fertilization but no zygote), hybrid inviability (embryo is not viable), hybrid sterility (resulting adult is sterile), and hybrid breakdown (first generation is viable but future generations are not).

Now consider weaning conflict in more mathematical terms. Choose the correct ratio in the following description of weaning conflict: When B and C are calculated from the mother's perspective, weaning conflict for families of full siblings should begin when B/C ratio is [1/4, 1/2, 1, 2, 4] and end when B/C ratio is [1/4, 1/2, 1, 2, 4]. Weaning conflict for families of half siblings should begin when B/C ratio is [1/4, 1/2, 1, 2, 4] and should end when B/C ratio is [1/4, 1/2, 1, 2, 4].

Full siblings: Start at 1, end at 1/2. Half siblings: Start at 1, end at 1/4. Note that mothers always initiate the period of weaning conflict when B/C (from their perspective) is 1; that is, benefit and cost are equal.

Choose the correct ratio in the following description of weaning conflict: When B and C are calculated from the offspring's perspective, weaning conflict for families of full siblings should begin when B/C ratio is [1/4, 1/2, 1, 2, 4] and end when B/C ratio is [1/4, 1/2, 1, 2, 4]. Weaning conflict for families of half siblings should begin when B/C ratio is [1/4, 1/2, 1, 2, 4] and should end when B/C ratio is [1/4, 1/2, 1, 2, 4].

Full siblings: Start at 2, end at 1. Half siblings: Start at 4, end at 1. Note that offspring should finally accept the end of weaning when B/C (from their perspective) is 1; that is, benefit and cost are equal.

How would mating with multiple males affect maintenance of gene diversity in cheetahs?

Genetic diversity in the population will be maintained

Bottleneck Effect

Genetic drift resulting from the reduction of a population, typically by a natural disaster, such that the surviving population is no longer genetically representative of the original population. (you get maybe 3 out of a population of an equal amount of blue and orange where 2 blue and 1 orange come out and everyone else dies, so when they reproduce you mostly see blue not orange so it looks nothing like the original. They just got lucky.) This has happened to both cheetahs and seals (hunting).

Founder Effect

Genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool composition is not reflective of that of the original population. (A new population is founded by a small number of individuals resulting in a loss of genetic variation. A small portion of people from Germany came to Pennsylvania and reproduced. But most of the offspring had 6 fingers or toes. This isn't because that trait is beneficial it just so happens that the founders of that population had this trait)

Post-Mating (Prezygotic Barriers)

Genomic incompatibly, hybrid inviability or sterility. - Mechanical Isolation: No sperm is transferred, lock and key because the egg and sperm are mechanically incompatible, they don't recognize each other (In fruit flies the male genitalia differs but some females have specific morphologies as well). - Gamete Isolation: Egg may not recognize sperm due to incompatible receptors.

What is Hamilton's Rule? What are the three mechanical terms, and how are they calculated.

Hamilton's rule states that an allele for altruistic behavior should spread if Br - C > 0. B is the benefit to the recipient, and C is the cost to the actor, both measured as number of surviving offspring. r is the coefficient of relatedness; it is the probability that two homologous alleles in actor and recipient are identical by descent. (Equivalently, it is also the percentage of the genome that the actor and recipient are likely to share.) r is calculated by tracing each possible pathway of relatedness between two individuals; every step between parent and offspring represents a 0.5 probability of any allele being shared. The probability for a whole path is (0.5)<n where n is the number of steps. Finally, the probabilities for each separate path are summed. (See pp. 2-4 for a review of this topic.)

Hybrid Sterility (Postzygotic)

Hybrid offspring mature but are sterile as adults (Mule)

Zygote or Hybrid Mortality (Postzygotic Barriers)

Hybrids don't always die sometimes they even outrank the parent species. However... When they do, isolating mechanisms: - Embryo dies shortly after fertilization (hybrid may develop but then die) - May not successfully complete development - Embryos of hybrids often fail to undergo metamorphosis successfully. - Larvae of closely related species are often very similar (it is in the specification of adult structures that species differ).

Developmental Constraints

If a potential adaptation cannot be formed during development to work with other parts of the organism, it will not exist.

March to Homozygosity

If alleles are selectively neutral (no differences in fitness), population will eventually drift to homozygosity (fixation) -Evolution has occurred by random process

What is the evidence that whistling is selfish and trilling is altruistic in Belding's ground squirrels? Was similar evidence presented for the black-tailed prairie dogs? What patterns in the data from the black-tailed prairie dogs suggest that alarm-calling is altruistic in that species too? How could you verify whether alarm-calling truly is altruistic in the black-tailed prairie dogs?

In Belding's ground squirrels, observations of actual attacks by predators documented that trilling doubles the squirrel's risk of being killed by the predator, while whistling decreases the squirrel's risk. Therefore trilling is definitely altruistic, and whistling is not, in this species. (It is important to note that not all alarm-calling behavior is automatically altruistic.) Similar data was not presented for black-tailed prairie dogs, and thus we cannot say for sure that this behavior is altruistic in this species. However, the patterns of the data shown in Figures 12.2 and 12.3 show that squirrels are more likely to alarm-call when they have kin nearby. This strongly suggests (but does not prove) that alarm-calling is altruistic.

Pre-mating (Prezygotic Barriers)

Isolating barriers that impede gene flow before sperm or pollen can be transferred to other species. - Isolation through time, temporal isolation: Incipient species in the same place (Brown trout and rainbow trout breed in different seasons). - Lack of contact through space: Habitat isolation, they spend their whole live in a single place so they don't get a chance to meet (European mosquitos, six different types, all breed in different habitats). - Lack of interest: Males might not engage females or females might not respond (Lacewings make calling sounds to try and attract females but because of the variation in male calls it becomes specialized over time and sometimes the female is only interested in certain calls) also in plants some like orchids have a specific fit between pollinators and plant.

Positive Assortative Mating

Mate with individuals LIKE yourself. Decreases heterozygotes, increases homozygotes

Negative Assortative Mating

Mate with individuals UNLIKE yourself. Increases heterozygotes, decreases homozygotes

Random Mating

Mating between individuals where the choice of partner is not influenced by the genotypes Equal chance of male/female pair, no choice or preference for a mate, no opportunity to pass up reproduction. As soon as they meet they reproduce.

Dispersal

Movement of individuals away from centers of high population density or their area of origin. (Allopatric, speciation in different geographic areas) - Involves movement of the organism

Do individuals evolve? Do they adapt?

No individuals do not evolve and they also cannot adapt. Adapting is a type of evolution, it's specifically changed through a type of evolution. (If a mutation in an individual occurs then it's only through selection that it might spread through the population)

Would a cooperative phenotype be maintained in a population in the presence of selfish phenotypes.

No, because selfish phenotypes out compete the cooperative ones (like in the public goods game). As soon as someone cheats its better for everyone to cheat, you can't match but you can make equal (Nash equilibrium, prisoners dilemma).

Polyandry

One female, several males. The oldest and largest individual is female, w/ multiple smaller males compete for access

Polygyny

One male, several females. The oldest and largest individual is male, w/ multiple smaller females compete for access. He maintains a harem of females whom he fertilizes.

Postzygotic Barriers

Reduced hybrid viability, reduced hybrid fertility, hybrid breakdown. Fertilization takes place, but may not result in successful offspring (Not surviving instantly or for only a short time). - Interaction of incompatible genes - Distribution of meiosis - Different number/structure of chromosomes

Intersexual Selection

Selection whereby individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex; also called mate choice.

Reproductive Isolation

Separation of a species or population so that they no longer interbreed and evolve into two separate species - Species are the outcome of reproductive isolation.

Synapomorphy

Shared derived character, a character that is homologous (of common ancestry). - May be transformed over time (fins to arms to wings or flippers) Example: Fish to tetrapods go to either birds or mammals then whales. - Characters that define the monophyletic group. (Wings are the synapomorphy for the monophyletic group of birds).

Gradual Evolution of Complexity

Simulation: -Run computer simulations so you can test if the vertebrate eye can function with changed parameters (shape, focal length, etc.) -Changed by 1% per mutation across different generations, and allowed it run, the mutations to occur randomly. Assessed what it did, increase (improve eye) or decrease fitness. -First, was improved depth perception, getting away more quickly or catch prey, etc. Which improved fitness. -Imporved lens, could see better and have a better field of view. Which improved fitness. -Took 400,000 generations to evolve complex vertebrate eyes to essentially signify what the human eye is today. -Shows that complex adaptations are simply adaptive steps that take place for a very long time.

Cooperatively Breeding Organisms

Some members forego reproduction while in the group. May risk death by defending the colony. Devote energies toward rearing of young of others (helping at the nest).

Parapatric Speciation

Speciation occurring when two populations have continuous distributions and some phenotypes in that distribution are more favorable than others (Through Fatherland, isolation by distance) - Physical Distance: Acts as the initial barrier to gene flow, isolation by distance. - Local Differentiation, no geographical barrier just physical distance. - Areas of overlap in range after speciation, hybrids may form is isolation is incomplete

Homologous Structures (Homologies)

Structures in different species are similar because of common ancestry. -Opposite of convergent evolution, divergent. Like the pentadactyl limb, in bats, dolphins, anteaters, moles, horses, monkeys, etc., the same bone looks different depending on the species (shortended, longer, thinner, etc.).

The Species Problem

The debate among biologists about how to define "species" and how to identify actual species Dog breeds, coyotes, and wolves are all capable of breeding but are all able to interbreed or A female horse and a male donkey make mules, but mules can't reproduce on their own. However, horses and donkeys are separate species.

Allopatric Speciation

The formation of a new species as a result of an ancestral population's becoming isolated by a geographic barrier. (Different Fatherland, nonoverlapping distributions). - Dispersal: Orangisms on a landmass, a new landmass appears and the organisms disperse to that new landmass they can create two different species between those two land masses because they are now geographically isolated. - Vicariance: Continent drifting apart, any geological event occurring, a part of the continent broke creating a geographic barrier creating two different species in two different locations because they were geographically isolated.

Speciation

The formation of new and distinct species in the course of evolution. - The mechanisms by which populations attain reproductive isolation (cannot achieve without reproductive isolation)

Sympatric Speciation

The formation of new species in populations that live in the same geographic area (Same Fatherland) - Speciation without a physical or spatial barrier, but you still need reproductive isolation. (Apple maggots, flies on apple trees look different so when apples came to NA the maggots moved to these trees which were in the same area as many other trees.

Summarize the logic behind the haplodiploidy hypothesis of eusociality. What is the evidence in favor of and against this hypothesis? Describe two other hypotheses for the evolution of eusociality.

The haplodiploidy hypothesis is based on the proposition that females are more closely related to sisters than to their own potential offspring. In this case, natural selection should favor the evolution of sterile female workers who raise sisters rather than raising their own young. In favor of this hypothesis, eusociality is particularly common in haplodiploid taxa, and female workers do manipulate colonies toward a female-biased sex ratio. However, not all haplodiploid species are eusocial, and many eusocial species are not haplodiploid. The major evidence against the hypothesis, however, is experimental evidence that relatedness among females is actually much lower than the hypothesis assumes. Because most colonies have multiple fathers and often multiple queens, most worker females are not more closely related to sisters than to their own offspring. Two alternative hypotheses are (1) eusociality may represent the best option for females in taxa that build complex nests and in which young require extended care. If solitary females have very little chance of establishing a viable nest on their own, raising siblings is probably the next best option. (2) Eusociality may evolve in taxa that live in extremely inbred colonies, such as naked mole-rats. (Note that this is similar to the haplodiploid hypothesis in its essential logic, i.e., r among colony members is proposed to be very high.)

Vicariance

The physical splitting of a population into smaller, isolated populations by a geographic barrier. (Allopatric, speciation in different geographic areas) - Involves environmental change

Homozygosity

The state of possessing two identical forms of a particular gene, one inherited from each parent. (2 identical alleles) f = (p^2 + q^2) or f = 1 - H

List the three features of true eusociality. Name two types of insects, and two types of non-insects, that have true eusociality.

True eusociality includes: (1) overlap in generations between parents and offspring, (2) cooperative care of offspring, and (3) specialized castes of nonreproductive individuals. Eusociality is found the Hymenoptera (bees, ants, etc.), termites, and a few other orders such as plant bugs and one family of beetles. It also occurs in at least two non-insects: snapping shrimp and naked mole-rats.

All of the following describe real experimental results. However, one does not support the predictions of Hamilton's rule. Which one? 1. Wood mouse sperm will sacrifice themselves to assist a "sibling" sperm to fertilize an egg. 2. Twenty percent of "in-law" bee-eaters that are not related to other birds at the nest will help raise the young anyway. 3. Prairie dogs are more likely to give alarm calls to a simulated badger attack if they have kin living nearby. 4. Coots have evolved discriminatory mechanisms to detect and reject eggs that are not their own.

Twenty percent of "in-law" bee-eaters that are not related to other birds at the nest will help raise the young anyway.

Evolutionary Stable Strategy

a behavior which, if adopted by a population in a given environment, cannot be invaded by any alternative behavioral strategy

Heterozygous Advantage

a condition in which being Aa, or carrying often times a bad recessive copy of the gene, proves to be an advantage in a particular environment, thus keeping the allele in population Ex: being heterozygous for sickle cell anemia in areas infested with malaria

Monophyly

a group (a clade or monophyletic group) including all the descendants of a common ancestor, a complete lineage - desirable classification - (Wings are the synapomorphy for the monophyletic group of birds or flippers are the synapomorphy for the monophyletic group whales).

Polyphyly

a group that does not uniquely share a common ancestor - undesirable classification

Paraphyly

a group with an ancestor and only some of its descendants - undesirable classification

Founder Event

a new, smaller population of "founders" break-off from the original population, but there's no apparent founder effect. (One trait doesn't become more frequent opposed to founder effect where either one trait becomes more frequent or one trait gets lost)

Haplodiploidy

a sex-determination system in which males develop from unfertilized eggs and are haploid, and females develop from fertilized eggs and are diploid

Nash Equilibrium

a situation in which each firm chooses the best strategy, given the strategies chosen by other firms

Copulation

act of mating; sperm deposited into female to fertilize ovum. Transmitting gametes Recognize the same species and right sex. Requires searching for mates which takes time

greenbeard effect

altruism directed only toward individuals with the same altruism gene (must code for behavior, signal, and recognition) - a theoretical model of a type of allele for altruistic behavior that could spread through a population via recognition of similar traits, without the involvement of kin selection or reciprocal altruism.

Inclusive Fitness

an explanation for altruism that focuses on the adaptive benefit of transmitting genes, such as through kin selection, rather than focusing on individual survival - Equivalence gained through support

Diploid

containing two complete sets of chromosomes, one from each parent.

Similar Selective Pressures in Convergent Evolution

factors in the environment that influence reproductive success in individuals (In nectivores: Nectar feeding, high metabolic demand, etc.)

Genetic Constraints

genetic variation for a particular phenotype may not be present within a population

Similar Morphologies in Convergent Evolution

help reinforce warning (In nectivores: Small bodies, long bills, agile flight, etc.)

Heterozygosity

in a population, the average proportion of genes for which a randomly chosen individual is heterozygous (2 different alleles) H = 1 - (p^2 + q^2) H = the chance of drawing 2 different alleles, the proportion of heterozygotes

Which of the following correctly complete the statement, "Reciprocal altruism directed toward non-kin may evolve when _______________"? 1. opportunities to offer altruism are rare 2. individuals that do not reciprocate are not remembered 3. punishment is rare 4. the cost to the actor is only slightly higher than the benefit to the recipient 5. individuals can recognize and remember other individuals

individuals can recognize and remember other individuals For a., "rare" should be "common." For c., the cost to the actor must be less than the benefit to the recipient. For d. and e., non-reciprocating individuals should be remembered so that they can be avoided and/or punished later.

Random Evolution

mutation, (migration) gene flow, and genetic drift Nonrandom evolution is natural selection (differential survival and reproduction)

Complex Adaptations

phenotypes influenced by many environmental and genetic factors with multiple components that must be expressed together to function (must be perfect, can't change any part) - Like the human eye, it doesn't survuve just as it's final form.

Spawning

process by which male and female fishes release their gametes near each other in the water Requires concentration and density if gametes appropriate to environment (gamete mortality high) Typically prevents extensive parental care Gamete recognition mechanisms

Analogies

similarities between organisms based strictly on common function, with no assumed common evolutionary descent

Phenotypic Plasticity

the ability of an organism to change its phenotype in response to changes in the environment.

Ubiquity and Longevity

the state of being everywhere at once (or seeming to be everywhere at once), everybody reproduces - Sexual lineages are around longer than asexual lineages, they have more longevity.

Optimality

the best possible outcome of a process, perfect adaptation. Adaptions aren't perfect and may look perfectly adaptions, but the poor design is good evidence for natural selection. (Works, but not ideal). -Vertebrate and Cephalopod eye: both look almost completely identical but the nerves are in front of the retina on the vertebrate eye has an inverted retina which creates a blind spot (having two eyes removes this because the brain works around this). But the cephalopod eye has nerves behind the retina which causes no blind spot.

Bateman's Principle

the idea that males experience greater variance in reproductive success than females - Eggs are the limiting factor, each female has a set number of eggs, once all the eggs are fertilized (given set per cycle/year) she's done. So, males have a higher reproductive success because they can always fertilize more eggs in a given cycle making their variance greater. Males w/ 100 offspring from 100 females, whereas women are limited to a number of eggs, 2 or 3 etc. The more offspring the more variance.

Mate Choice

the intersexual selection of a mate based on attraction and traits (Size, pattern, color, overall health, genetic qualities, etc.) - Females are pickier because they have the more expensive gametes, a larger investment in reproduction (they not only have a limited amount of eggs but they also have to raise and produce the offspring depending on the species). They obtain the best mate so that her investment in eggs pays the greatest genetic dividend. - Cues include health/ capability (greater fitness). Minimize wasted time/effort (the greater distinction between male/female). Decrease possibility of interbreeding.

Kin Selection

the process by which evolution selects for individuals who cooperate with their relatives (Their kin: offspring, nieces, etc.) recent, common descent.

Altruism

unselfish regard for the welfare of others Reducing ones own fitness while increasing the fitness of another individual.

Hamilton's Rule

when C < r x B C = cost to the altruistic party r = genetic relatedness B = fitness benefit to recipient of altuism

Pre-adaptation (Exaptation)

when an organism's existing trait is advantageous for a new situation - An existing structure that has been modified to serve a new function