BIO 281 Exam 2 Study Guide

life expectancy

(Ex) The mean amount of time an individual of age (x) is expected to live. To calculate E(x) you must first calculate Lx, the average number of individuals alive in an age category. Lx = (Nx + Nx+1 ) /2 Tx = Sum from x-->n of Lx

Batesian Mimicry

A benign species that resembles a noxious species.

outbreeding depression

A decrease in fitness that arises when genes from two locally adapted populations are mixed because the new combinations of alleles break up adaptive combinations.

sexual selection

A form of natural selection in which traits that enhance the ability of one sex (usually males) to compete for or attract mates are favored. operates in two basic ways: - female choice: Male phenotypic traits may become exaggerated by this selective force. - male-male competition: Direct (male to male physical competition) or indirect (competition for resources that will attract females). At a point, intense sexual selection on males reduces their fitness. Balance hypothesis: male traits are exaggerated by female choice until their overall fitness cost is too high. Each trait has a fitness cost and benefit. "truth in advertising" hypothesis: elaborate phenotypic traits of males are an indication of overall fitness. Females can only make so many offspring, so male-male competition is a good way to look at the quality of potential mates. If males are able to cope with the fitness costs of their elaborate phenotypic adaptations (the ones used to court females), then that is a good indicator that they are fit.

Population

A group of individuals of a single species inhabiting a particular area. Ex: Moose on Isle Royale in Lake Superior. On the island there is a distinct boundary to the groups range and thus to the population.

K-selection

A life history strategy in which the reproductive strategy emphasizes the investment of a large amount of energy in a small number of offspring

serial monogamy

A mating system in which each male mates with one female. This relationship lasts for just a single breeding season; in subsequent breeding seasons the male mates with other females. Molecular techniques like DNA fingerprinting show that pure monogamy is rare. Extra-pair mating occurs in most species that pair bonds. Even in species in which some extra-pair mating occurs, the mating system may be skewed toward monogamy under certain ecological conditions. for example is successful rearing requires both parents. If the seasonality and resource phenology lead to high reproductive synchrony in the population, monogamy is more likely because when most females are mated, a male would probably gain less from seeking additional copulations than remaining with his mate and providing parental care.

polygyny

A mating system in which males mate with more than one female. The most common relationship between males and females. Has advantages to males -- they benefit from mating with many females. The benefit of females is less clear. possible benefits to females: increased lifetime reproductive success due to larger group sizes may compensate for the cost of sharing a mate at each reproductive event. The energetic cost of ensuring monogamy may be too much. The selection on females probably favors any means by which they shift the balance toward monogamy.

Heritability

A measure of the proportion of the total phenotypic variation that is due to the additive genetic variation.

evolutionary stable strategy

A mutation or adaptation that can increase in frequency in the population when it is rare.

population bottleneck

A phenomenon in which a population declines to small numbers and then expands again.

group selection

A process analogous to natural selection in which the population (rather than the individual) is the object on which selection acts.

Migration:

A seasonal movement from one region to another and back. has genetic and environmental control. Selection for individuals with greater unrest and mobility during a certain seasons results in lines with higher migratory tendency.

coevolutionary arms race

A set of adaptations and counter adaptations in exploitative interaction.

key demographic characteristics of a population

Age structure Sex structure Variations in individual reproduction and survival. allow us to analyze and predict the growth or decline of a population. Age structure: The distribution of individuals according to their ages. --> we can infer the patter of reproduction by the proportion of young individuals in a population. Life table: We represent age structure information in standardized form using life tables. It is a table showing the numbers of individuals of different ages and their age-specific mortality and reproductive rates.

common gardening experiment

An experimental design that distinguishes between genetic variation and phenotypic plasticity. Phenotypically different plants from different environments are grown in a common garden. Differences that persist are genetic a, similiiar phenotypes in the common garden indicate phenotypic plasticity. Ex: Common Yarrow in California --> grows in a wide range of habitats and has a wide range of observed growth heights. There is evidence of both genetic diversity and phenotypic plasticity. Small plants in the high-elevations are small no matter where they grow. o

parasitoid

An exploitative interaction. Parasite: species that live in or on another species, the host, and obtain energy from its living tissue. Causes harm but necessarily death. Host is nutritionally important and constitutes the habitat for the parasite. Parasitoid: Specialized group of insects whose offspring develop in the body of another speceis of arthropod. As they consume the tissue of the host from the inside, they eventually kill or sterilize the host species.

Sessile Organism

An organism that is attached to a substrate (ex: a rock) and cannot move around easily.

Altruism

Any behavior that increases the fitness of others at the expense of that altruist's fitness.

Attributes of her offspring that enhance the fitness of a female include: a. Gender b. quantity c. quality d. all of the above e. a+b f. a+c g. b+c

C

The most common mating system in nature is a. strict monogamy b. serial monogamy c. polygyny d. polyandry

C

competitive exclusion principle

Competitive Exclusion: The extinction of one species due to competition from another Competitive exclusion principle: The concept that two species cannot coexist on a single limiting resource.

identical by descent

Describes two copies of a gene that are derived from the same ancestral copy of the gene.

sexual dimorphism

Differences in physical characteristics between males and females of the same species. Different selective forces act on males and females. Typically it is the female that parts a significant selective force on the males. The sexes differ in this way due to fundamental differences in their reproductive roles. Females bear the direct anatomical, physiological, and energetic costs of reproduction. There is a point where female fitness cannot increase by producing more young. Rather, it increases with the quality of the young she produces. Male fitness is the product of the number of females impregnated.

Ecological vs evolutionary population

Evolutionary biologists and ecologists define the population differently. The genetic change in a population that occurs by evolution results from some combination of the following: natural selection, gene flow, genetic drift, and mutation pressure. Each of these processes operates on the gene pool, the summed genetic constitution of the population. Evolutionary biologists use the term deme to refer to denote a local group of individuals that mate at random. The genetic change that defines evolution occurs because of increases or decreases in certain genotypes. And genetic change is intimately tied to the environment and thus the ecological population. Teh size of the deme is determined by ecological factors acting on the population. Any ecological process that reduces the population size is also likely to reduce the size of the deme. The discontinuities that define the evolutionary and ecological populations often coincide.

Adaptive responses to local environmental variation:

Ex: Due to increased logging and habitat destruction, the size of conifer forest systems has declined and they have become more sparse. What we see is that forest birds are occupying more open forests with larger spaces between patches. Pointed wings have thus become more common as this adaptation allows them to increase mobility and efficiency of sustained flight. Ex: of intraspecific variation: Land snail. the color patterns on muesuem colocations of these snails correlate strongly wth the vegetation background in different regions: The banding pattern camoflages the sanil in its native habitat.

territoriality

Exclusive use of a portion of the home range. Intraspecific and sometimes interspecific aggression maintains exclusive access to the resources of the territory. The defended area is determined by the trade-off between the energetic cost of defense and the gain due to exclusive access. The size of food resource territories increases as a function of body mass. Large animals have larger territories than predicted simply on the basis of their energetic needs. This is because large animals share more of their territories with other individuals than do small animals. They have less exclusive use of their territory and need larger territories to compensate. territory size is also related to the process of sexual selection and the mating system. Territory size reflects resources and can attract females.

In animals, protandry is more common than protogeny. True / False

False. Protogeny is more common*

semelparity

Females produce once in their lifespan. BIG BANG if produced at unfavorable times, the whole clutch can be lost Ex: Salmon. They make a energetically costly journey to their natal waters, and it may be impossible to make this trip multiple times so they just have one big reproductive event. iteroparous/iteroparity: Females that spread their reproductive effort out over a longer period of time. Organisms with Type II or III survivorship curves are more likely to survive from one reproductive event to the next. - increases the odds that the condiitions will be favorable for her children at some point. -if associated with smaller clutch sizes, each offspring may be larger or recieve additional parental investment that increases chances of success.

Plant reproduction includes a. autogamy b. outcropping c. apomixis d. hypomixis e. all of the preceding f. a+b g.a+b+c h. a+b+d

G

Increasing genetic variation:

Genetic variation arise from mutations. Mechanisms increase, decrease or maintain that variation. Sexual reproduction is among the most important of these. Sex increases the number of new combinations of genes. Meiotic process itself increases variation through gene recombination. disruptive selection maintains genetic variation in the population because more than phenotype is adaptive and selection ensures that each persists.

ruderals

In Grime's triangular model, plants that are adapted to environments with high levels of disturbance and low levels of stress. page 235

kin selection

Inclusive fitness theory is the precursor to this idea. A form of selection in which selection operates on the kin group. Kin selection can lead to the evolution of altruistic behaviors. How do individuals recognize Kin? in some systems, recognition may not be necessary. In Belding Ground Squirrels the Males disperse from colonies before breeding so its only females and their kin. Because of sex-based dispersal, females who call are likely to be warning their kin. Olfaction seems to be an important indication of Kin (in mammals at least). Kin discrimination is greater in species where the average relatedness of the group is lower. Honeybees are Haplodiploid. Females are the diploid products of fertilized eggs. males are the haploid products of unfertilized eggs. Haplodiploidy changes teh coefficient of relatedness between sibs and parents-offsprings. In most organisms (r) is 0.5 between parent and offspring. But in Haplodiploids sisters are related by 3/4, where parent and offspring is still 0.5. Sterile sisters give up their own reproduction to help their queen sister.

What defines the Boundary of a population

Individuals are not homogeneously distributed across the landscape. Differences in demographic parameters, such as the number of individuals, their spacing in the habitat, and their reproductive rate, distinguish local groups. In practice, ecologists define the boundaries of a population on the basis of these kinds of discontinuities, that is, sharp changes in the demography. Population boundaries are also largely defined by the movement of individuals.

presaturation dispersal

Individuals that disperse begore the habitat is filled or resources are limiting. reasons: in some vertebrate species, dispersal is sex-based. in birds, most dispersers are females; in mammals, most dispersers are males. This is due to a difference in bird and mammalian mating systems. Birds tend toward monogamy and territoriality to attract females, where mammals are usually polygynous. Thus, males that cant compete with others for mates so they are better off dispersing. In birds, familiarity with the environment increases the chances that a male will find a mate, so dispersal isn't super advantageous in that instance. sex-based dispersal reduces the rate of inbreeding for both dispersers and philopatric individuals.

Mullerian mimic

Mimicry represents another set of complex coevolutionary interactions that arise when prey are toxic or otherwise dangerous. def: groupsof toxic or unpalatable species that resemble one another. ex: Bees and wasps

polyandry

One female, several males. Rarest of all the mating systems. benefits: higher reproductive success in some cases. This is because females may increase the probability that they mate with a genetically superior male. Dilute the significance of any matings with related males --> reduce inbreeding depression.

Plant mating systems

Outcrossing: Mating among different individuals Autogamy: Self-fertilization Apomixis: Asexual reproduction Plants vary enormously in the arrangment and distribution of male (pollen and anther) and female (egg and ovary) components of the reproductive system. monoecious species: have male and female parts on the same individual Dioecious species: some are males, some are females. Superimposed on these patterns is the second key component of the mating system: the degree of self-incompatibility - the barriers to selfing. Genetic selfing incompatibility is based on a set of alleles, SI genes, that is identical in the pollen grain and stigma, prevent growth of the pollen tube and fertilization. Protogynous: plants whose female parts develop and mature before the male parts. Plant mating systems affect the degree of selfing, and this in turn affects the degree of inbreeding in the plant. Plant species that colonize new habitats after long distance dispersal tend to be hermaphroditic and self-compatible. Apomixis is advantageous in species that rapidly exploit local resources or ephemeral favorable conditions.

pollination syndrome

Plant pollinator mutualisms are widespread and widely understood transportation mutualisms. flower and pollinator have different ecological goals in this system. The flower needs transportation of the pollen, and the pollinator is foraging for nectar or pollen from the plant. This mutualism blurs the lines. for the plant it is transportation mutualism; for the pollinator it is nutritional mutualism The suite of flower characterisitcs that attract certain pollinator types are consistent enough to be refered to as the pollination syndromes. pollination syndromes: Adaptations to attract a potential pollinator and ensure that pollen can be transferred from the stamens to the the pollinator and from the pollinator to the stigma. include: Size, shape, and color of the flower, and the reward offered to the pollinator. ex: bat oriented flowers open at night, on the top of the plant and are fragrant butterfly oriented plants have large open landing platforms. some produces structures that the butterfly can take with it. bee oriented flowers have landing guides that orient the bee and tell it where to go.

density dependence

Population processes that change with the population density.

mating system

Sexual selection is the consequence of the different reproductive strategies of males and females. the length of relationships between males and females, the relative contributions of males and females to parental care, and the number of mates an individual copulates with.

Decreasing variation:

Stabilizing selection: eliminates extreme phenotypes and their genotypes, resulting in reduced variation in the population. directional selection: favors pehnotypes at one end of the bell curve and selects against those at the other end --> reduced overall variation Inbreeding: Increases the frequency of homozygotes and decreases the frequency of heterozygotes. variation is lost in two ways. Heterozygotes are themselves a form of genetic variation due to their two allele combination. The increase in homozygosity exposes recessive alleles to natural selection. recessive alleles are eliminated that would otherwise be protected in heterogeneous individuals. Genetic Drift: allele frequencies shift stochastically. Some alleles become fixed while others are eliminated totally --> eliminates variation.

(T/F) Behavior is a phenotypic trait

T*

Environmental Variation over time.

Temporal change occurs on many scales. Light and temp change daily, and on a seasonal scale. In the intertidal zone, some sessile species experience both exposure to air and submersion twice a day and thus two radically different physical environments. Although pattern of change is important, the speed of the change is also important. For some organisms, unpredicatability poses a greater challenfe than a constant environment. spatial variation interacts with temporal variation. ex: dry grassland habitats will have seasonal rains that create short-lived pools of water - vernal pools. As the ponds evaporate, the moisture conditions change drastically from the edge of the pond to the middle. --> temporal and spatial gradient of soil moisture. annual plants respond to this with rapid growth where they can find moisture.

demograhic transition

The changes in the relative size of the birth and death rates in human population from preindustrial to industrial species.

monoecious

The concept of sex-ratio is complicated in plants due to the arrangement of sex organs on the plant. monoecous plants: Have both male and female function on the same individual. In some cases, each flower contains both stamens and pistils. For monoceous plants, the traditional sex ratio does not apply.

inbreeding depression

The decrease in fitness caused by mating between close relatives due to offspring inheriting deleterious alleles from both the egg and the sperm. reduces reproductive rate and increases mortality. If the population contains many deleterious alleles masked in heterozygotes by beneficial dominant alleles, there may be strong selection to avoid inbreeding. Thus if inbreeding costs are high, the fitness advantage of inbreeding avoidance can outweigh the mortality cost of movement -- see pre-saturation dispersal.

Connectivity

The degree to which populations are connected by dispersal of individuals. Populations with high connectivity tend to differ less than those with low connectivity. Greater movement of individuals in a population allows for more homogenization of genomes. Where the exchange of individuals is more frequent, demographic discontinuities are less likely to arise and persist. The nature of the ecological populations under study define the boundaries of the population. Ex: Population of a particular fish in the Great lakes vs the population of a particular fish in one or two of the great lakes (a comparison). Defining a population is a question of scale - what spatial scale - what size area - is appropriate for the ecological question we are addressing? spatial scaling is more important to populations of sessile organisms.

Neoteny

The devlopment of sexual larval forms that no longer metamorphose into adults in metamorphic species. Ex: some populations of the spotted salamander. selective forces leading to neoteny are not fully understood. However, this phenomenon seems to be more common in extreme environments such as high alititude where temperature regime in the terrestrial environment is too low for poikilothermy. Also tends to occur more when the aquatic environment is unusually productive. page 226

deme

The evolutionary population unit; a group of randomly mating individuals. For evolutionary biologists, the deme is the relevant population concept. The deme and the ecological population are intimately connected.

niche overlap

The extent of common use of the resource by two or more species is quantified by the amount of niche overlap (a)

Bet-hedging strategy

The idea that organisms that experience unpredictable environments should reduce variation in fitness by spreading out the risk of reproductive failure.

carrying capacity

The number of individuals that can be supported by the resources available to a population (K). Not an actual tangible value that can be directly measured.

Key demographic parameters of a population:

The number of individuals, their distribution in space, and the characteristics of the individuals in the population. The most basic demographic aspect of a population is the number of individuals it contains. total number of individuals is represented by (Nt). We represent the number of individuals in terms of population density.

fecundity

The number of offspring produced. It can be measured for a single reproductive event or over a lifetime.

Measuring spatial distribution of individuals in a population:

The pattern of spatial distribution of specific individuals is the population dispersion. There are three potnetial dispersion patterns in populations: 1. random distribution in the habitat. 2. Clumped dispersion pattern: groups of individuals clumed together and separated from other groups. 3. Evenly distributed at regular intervals. The three patterns grade into each other. One solution to answering what distribution pattern a population has is a poisson distribution. The distribution is a random pattern that applies to relatively rare events. We compare the actual pattern of distribution to the theoretical distribution of the population. if they match, the distribution is random, if not, it is either clumped or regular. To use this method, a grid is laid over the dispersion pattern such that each grid square is small. We calculate the expected number of grid squares with certain numbers of individuals under teh poisson distribution. Px = (a^xe^-a)/(x!) under the poison dist, if the mean/variance ratio = 1, the dispersion is random. If we reject the poison distribution, we must then determine if the dispersion is clumped or regular. A mean/variance ratio >1 occurs if the variation among squares is small, indicating a regular dispersion pattern. In contrast, when the mean/variance ratio is <1 that indicates a clumped distribution. The dispersion pattern may change depending on the scale by which the population is analyzed.

intrinsic rate of increase, r

The potential growth rate of a population based on the difference between the per capita birth and death rates, measured at small population size.

coefficient of relatedness

The proportion of genes that shared by two individuals. Parent-offspring: 0.5 Full sibs: 0.5 Grandparent-Grandchild: 0.25 Aunt/Uncle-niece/nephew: 0.25 First Cousins: 0.125

Janzen-Connell Hypothesis

Tropical treees tend to be widely scattered: most show a random or regular dispersion with large distances between adults. The hypothesis proposes that seed predators and herbivores are responsible for this pattern. The greatest concentration of seeds is by adult trees. Seeds that are far away from adult trees have that greatest probability of survival --> explains this pattern.

Female choice operates in lek species. True / False

True

Poisson Distribution

Used to measure the spatial distribution of individuals in a population. Is a species randomly distributed across space? A random pattern that applies to relatively rare events. We compare the actual pattern of distribution to this theoretical random distribution. If they match the dispersal is random, if not, the dispersal pattern is either clumped or regular. page 183

metapopulation

Variation over spave is another important component of the interaction of regulatory mechanisms. For most species individual populations are connected are connected as a larger complex of populations. Thus we need to consider each population in a broader landscape perspective. Metapopulation: A group of populations connected to varying degrees by dispersal. Embedded in a landscape composed of habitats of varying quality and suitability. Some populations within the meta population inhabit discrete regions of high quality habitat. Other parts of the habitat may be lower quality and house smaller ephermeral populations. The poptential for dispersal varies with the mobility of the species and the nature of the habitat across the landscape. linear segments of appropriate habitat may constitute dispersal corrdiors that connect populations. page 216 ex: Checkerspot butterfly the larger its habitat patch, the lower the frequency of extinction; the more distant the patch, the lower the probability of recolonization. Many factors affect metapopulations: - density dependent and independent - biotic and abiotic --> these differentially effect each local population. The result is that each local population has its own pattern of scarcity and abundance. NONE achieves equilibrium or stability, but the metapopulation is comparitively stable becuase it is composed of populations that fluxuate independently. Stability occurs at the landscape level even though individual populations fluctuate Ex: Adelie penguin. Shifting ice conditions and the movement of large icebers change the size, isolation and resource conditions of individual populations.

optimal foraging theory

a body of theory that tries to identify the best foraging strategy by which an organism can maximize total energy or energy per unit time. based on the relative costs and benefits of an organism's actions. For a predator, fitness is maximized by making choices about what to eat and how to capture the prey so that the benefit exceeds the cost. the currency that underlies this cost-benefit analysis is energy - the net gain or loss of energy through different predation strategies. each predatory behavior has a cost and a reward. Predation strategies are genetically controlled and thus subject to natural selection. decisions a predator makes has fitness consequences. two kinds of energy constraints. - some are energy maximizers --> fitness is highest when they return the highest toal energy return from predation - others are time maximizers. --> fitness is highest when they obtain the highest toal energy return of energy, the most calories per unit time. Predators that are calorie limited tend to be energy maximizers. Even if the time requirement cuts into other things, the need for calories overweighs that burden For time maximizers, other tasks like courtship, mesting or migration require energy be obtained as efficiently as possible so that there is time and energy for these other tasks. Search time (S): The time time required for a predator to locate and identify an iteam of food Handling time (h): Teh time required for a predator to captur, subdue and consume a prey iteam

inclusive fitness

a concept of fitness based on the relative ability of an individual to transmit its genes or copies of them to the next generation.

frequency dependent selection

a form of natural selection in which the fitness of a gene is determined by its frequency in the population. Rare phenotypes have an advantage when selection is frequency dependent. ex: elderflower orchid. has yellow and purple varities of different frequencies --> as the bee moves from purple --> yellow --> whatever it looks for a reward but ultimately finds none. After every purple sampling, a yellow flower is sampled --> yellow benefits more than its actual percentage of the population would otherwise give to it.

female defense polygyny

a form of polygyny that occurs when groups of females are guarded by males. aggregated females require less energy to guard and maintain than widely scattered individuals. The spatial distribution of females is, in turn, determined by the distribution of ecologically important resources. common in ungulates and pinnipeds.

protandry

a form of sequential hermaphroditism in which the individual matures first as a male, then transforms into an adult female later in life. female function is more energetically costly than male function. In jack-in-the-pulpit, individuals can change gender multiple times. Can be developmentally programed and always occur at a certain age, or can be triggered by environmental or social conditions.

genets

a genetically distinct individual in a plant population. Genets may compromise many individuals, especially when reproduction is by cloning.

static life table

a life table based on a sample of the population and the distribution of individuals of different age

cohort life table

a life table based on following a single cohort from birth to the death of the last individual.

interference competition

a mechanism of competition in which one species actively inhibits another from obtaining the resource

exploitation competition

a mechanism of competition in which one species reduces the amount or availability of the limiting resource

Lincoln Index:

a method for determining population size by marking and recapturing portions of a population. the relative numbers of marked and unmarked individuals in the second capture can be used to calculate the total population size. previously captured and marked individuals: (Nm), unmarked individual (Num). N= Nm(N2/Nm2)

transportation mutualism

a mobile species is rewarded for moving gametes or individuals of a sessile species pollen and seed dispersal are the two most common forms. Range from obligate and highly specific to generalized and facultative. Birds and seeds. Bonobos and Tamarind trees. seed dorminancy breaks as they pass through the bonobos gut and then are transported many kilometers away. missletoe and Tangers. The missletoe has a pulp layer that protects it from the birds digestive tract and clings to the outside of the bird. The bird will fly away and rub it off on another tree --> that infects the tree with the missletoe parasite, starting the cycle again. The Tanger has a gizzard that will let the missletoe seeds pass through unharmed, it will crush bugs but not this seed.

ramets

a physiologically distinct individual in a plant population

survivorship curve

a plot of the log lx as a function of age. Graphically represents the pattern of age-specific survival. Vary widely among species. three broad patterns emerge: Type I: Low survival in young ages, then high survival until old age where mortality rises rapidly. Type II: Survivorship is constant across all ages, leading to a linear relationship between Ic and age. Type III: Early mortality is very high, but decreases with older age. typically annuals have Type I curves, perennial plants that reproduce just once have Type II curves, Polycarpic perennials (long lived plants that reproduce repeatedly) have type III curves.

functional response

a predator response to increased prey numbers in which each predator consumes more prey

direct development

a process in which the adult develops from the fertilized egg without a larval stage

Index of relative abundance

a quantitative measure of the relative size of a population using indirect evidence of the presence or absence of individuals. can use fecal pellets in some cases. in other cases, the number of individuals encountered on a set of systematic paths through the habitat or transect correlates with abundance. Indices of relative abundance can also provide population information back in time where direct counts are obviously impossible. --> ex: larch moths and trees. Larch months retard the growth of the trees and the growth rings of the tree can be used to record the abundance of moths during a specific time.

character displacement

a shift in the niches of competing species that reduces competition among them. Natural selection favors those individuals in each species whose resource use overlaps less with that of the other species

lek-mating species

a species that uses a form of polygyny and female choice in which males gather to display to females on traditional places. Sage Grouse and Prarie Chickens use this method.

Keystone mutualist

a species whose participation in webs of mutualistic interactions is vital to the function of the community

stimulus-response

a specific behavior is elicited by a specific stimulus. Central to animal behavior. for example, a band of red coloration on the side of a male stickleback fish stimulates aggressive behavior in other males. Red is the stimulus; aggression is the response. Highly stereotyped; the behavioral response is invariant --> courtship rituals exemplify this. Ex: Waved Albatross, the male and female take turns doing very specific actions that each illicit another specific response, if either does not perform the prescribed behavior the courtship breaks down and they do not mate. This behavior helps to ensure conspecifics - no eggs or sperm are wasted on interspecific mating.

diapause

an embryonic stage in which the embryo does not implant in the uterus and suspends development

communication

any action on the part of one individual that alters the probability of behavior in another individual. An important aspect of behavioral interactions among conspecifics. Some stimulus-response systems are a form of communication. But communication can be more complex and can convey a range of info or elicit a range of responses. The optimal choice of the signal is dependent on the physical properties of the environment and the nature of the communication. Ex: Whales use frequencies that travel far in water instead of chemical signals.

altruistic behavior

any behavior that increases the fitness of others at the expense of that altruist's fitness Ex: alarm calling behavior of a Belding ground squirrel is altruistic. How do such behaviors arise if they can lower the fitness of the altruist. W.D Hamilton solved the problem --> One can promote one's genes in future generations directly or indirectly. A individual can derive fitness benefits from individuals who carry some of the same genes. Hamilton proposed that genes for altruism can increase in frequency if: (rB - C > 0) where r is the coefficient of relatedness. where B is the fitness benefit to the recipient And where C is the fitness cost to the altruist. How does an altruist know that his action will benefit their kin?

eusocial

describes a complex social system in which there is a division of labor or castes, a high level of cooperation, and sometimes altruism. --> honeybees, ants, and termites. Termites are not haplodiploid yet show the same level of reproductive altruism seen in other insect species. Few vertebrate employ this system. Bird examples: Acorn woodpecker, Seychelles warbler, Florida Scrub-Jay, and Groove-billed ani. the ecological situation, especially limited opportunities to breed and high adult survival are important correlates of cooperative breeding. Naked mole-rat. Employs breeding and working strategy that means that the average (r) is as high as .81.

Iteroparous

describes a reproductive strategy in which females reproduce more than once over the life span

dioecious

describes a species in which the male and female reproductive organs are carried on separate specimens

philopatric

describes individuals that do not disperse. They stay in their natal environment.

Diploecious / monoecious / dioecious / ambioecious plants have distinct male and female flowers.

dioecious

saturation dispersal

dispersal of individuals that occurs when the habitat is filled or resources is limiting. These individuals have no choice but to seek better conditions elsewhere.

aposematic coloration

distinctive, conspicuous color patterns that signal that the individual is toxic or unpalatable

protogyny

ex: Rainbow Wasse, the social group dynamics determine whether sex change occurs. Large bright colored males do most of the mating, if no such male exists, a female turns into a male. Describes a pattern of sequential hermaphroditism in which female function develops first.

intraspecific variation

genetic or phenotypic variation within a species. Subspecies: A local phenotypically distinct form. Race and subspecies are synonymous. the essential feature of intraspecific variation is that the phenotype varies with the patterns of environmental variation. two basic ways that this occurs: Ecotypes, and phenotypic plasticity. spatial variation in the environment is due to discontinuities in physical and biological factors from place to place. Three key aspects of these discontinuities are key to the origin of intraspecific variation: 1. The magnitude of the differences between patches - determines the selective pressure exerted on the organism. When local environments differ drastically, the potential impact is exaggerated. The differences between adjoining habitats are important, an animal camouflaged in one stick out in another. -Ecotones are boundaries between habitat types. They reflect the shifting mosaic of spatial variation. The response to the mosaic depends on how sharp the differences are from place to place. 2. The degree to which the patches are isolated. - the isolation and spatial scale of environmental variation also determine the potential adaptive response of the organism Environmental variation in which the patches are large relative to the mobility of the organism is known as coarse-grained variation. 3. The relative size of patches.

microhabitat

habitat: the general features of the environment important to the animal. microhabitat: The subset of the habitat that differs in important abiotic and biotic characteristics. Microhabitat selection is important for many species as a means of maintaining homeostasis. The pattern of use and movement through the habitat and even the microhabitat is not usually random.

ecotypes

locally adapted and genetically distinctive populations within a species. key word: Intraspecific variation. How do they arise: Adaptations arise by natural selection operating on the specific genetic variation. Directional, disruptive, and stabilizing selections eliminate some variants and favor others. The amount of variation on which these selective forces can act is important. Ecotypic differentiation is more likely to occur if the spatial variation in the environment also includes barriers to gene flow among populations. Gene flow tends to oppose local natural selection. Immigrants usually homogenize the genes of a local population. If local genetic variation has declined during ecotype formation, the population may have a dimished adaptive ability known as adaptational lag.

extra-pair matings

matings outside the pair occur with fair frequency, and a significant minority of offspring result from them.

Measuring Genetic variation in a population

must first distinguish between genetic variation and phenotypic plasticity. --> one way to do so in plants is the common garden experiment. direct sequencing of DNA provides a measure of genetic differences among individuals. Molecular techniques measure variation in a much larger proportion of the genome than specific traits. Some molecular markers, like tandem repeats in fingerprinting, have no phenotypic effect. these are selectively neutral.

protection mutualism

one species provides a benefit or reward to another that provides protection from predators, herbivores, or parasites. ex: The anti-acacia mutualism describes this. In this case, both species derive some protection. active defense of the plant by the ants and the thorny nest sites for ants. important set of protectional mutualism occurs between plants, especially grasses and trees, and fungi. The fungi makes alkaloids that deter grazing, and the fungi receives photosynthetic energy from the plant.

unitary organisms

organisms that exist as separate and distinct individuals Most animals are unitary. They develop as separate individuals from the zygote according to strict and sometime irreversible patterns of development. modular organisms: develop and increase in size by repetitive patterns of growth and development.

Allopatric

populations that are geographically separated from each other

asexual reproduction

process of reproduction involving a single parent that results in offspring that are genetically identical to the parent

demography

quantitative study of populations demographic attributes of a population include measures such as the number of individuals, the proportions of males and females, and the patterns of survival and reproduction of individuals of different ages. Vary both spatially and temporally. Quantifying both space and time will let us understand and predict how populations grow and decline.

self-regulation

regulatory mechanisms within the organism that operate in a density dependent fashion. Self-regulation requires taht internal mechanisms affect teh components of the basic equation: r = (b+i) - (d+e) in a density dependent fashion ex: territoriality, if access to resources is needed for successful reproduction, then b is compromised. in some species, high density leads to crowding, competition, and increased aggressive interactions among individuals. This in turn can effect physiological changes i nthe individual such as stimulating the production of stress hormones. Under stressful conditions physiologic changes can potentially increase mortality or decrease reproduction. If so, internal density dependent mechanisms decrease the population size. At lower density these effects are reverese This kind of regulation is not restrained by the principle of ESS because in essence high density causes pathological changes that ultimately decrease the population size.

life table

represents age-specific survival data for a population. Shows the number of individuals in each age category as well as a set of age-specific parameters such as mortality, reproduction, and life expectancy. Generally obtained in one of two ways: Cohort or static Cohort life table: A life table based on following a single cohort from birth to the death of the last individual Static: A life table based on a sample of the population and the distribution of individuals of different ages. Nx represents the number of individuals alive at the start of each age category Lx = age specific survival. The proportion of newborns surviving to age x. calculated by dividing Nx by No. Dx = the number of individuals dying at each age. Page 187

coarse-grained variation

spatial variation in the environment that is large relative to the mobility of the organism The organism tends to experience just one or perhaps a few different environments because its movement is small relative to the scale of the spatial variation in the env.

fine-grained variation

spatial variation in the environment that is small relative to the mobility of the organism. Individuals will experience many env. An env that is coarse-grained for one species may be fine-grained for another.

cost of meiosis

the 50 percent reduction in the number of a parent's genes passed on to the next generation via sexual reproduction versus asexual reproduction

phenotypic plasticity

the ability of an organism to produce different phenotypes in different environments. non-genetic. ex: Oak trees that grow in deep shade produce wider leaves with smaller indentations. Marine iguana exemplifies this. During el nino shifts in the water temperature cause changes to the concentration of red and green algae --> this reduces the primary food source for the organism and thus reduces overall reproductive capability and food becomes scarce. As a result, Iguanas are ~20% smaller during this time compared to other periods of time, this is a phenotypic adaptation to scarcity, not a genetic one. not all phenotypic plasticity is adaptive. Some of it may be due to the detrimental impacts of poor habitat. adaptive phenotypic plasticity requires a mechanism that only detects an environmental change, but alters the developmental pathways so as to produce the optimal phenotype. This characteristic is both the advantage and the burden of phenotypic plasticity: the organisms can respond to its env, but the developmental complexity and energetic requirements for phenotypic changes may be a burden. in environments where variation is fine-grained, the organism typically experiences many ecological conditions. A single genotype can develop more than one phenotype based on the env it encounters. In singular env, a genetically fixed adaptation may be better. see: Intraspecific variation.

adaptive radiation

the diversification of a group of organisms into forms filling different ecological niches.

reproductive value

the expected reproductive contribution to the next generation of an individual of age x. Reproductive value is closely tied to the organism's fitness changes over the course of the life span because the age-specific survival and birthrates determine the number of offspring in the future (and those will change). All components of Life history contribute to Reproductive value -development -lifespan -reproduction integrates the components of life history. The effects will manifest in the individuals reproductive value. Selection operates on the life history only if the differences among strategies have a genetic basis. Life history may vary among individuals due to environmental effects. nongenetic variation of this is phenotypic plasticity.

Bateman's principle

the idea that males experience greater variance in reproductive success than females The opportunity for selection to affect one sex increases with the degree of sexual dimorphism. There is strong selective forces among males to increase their opportunity to mate or the # of matings they achieve. Females have a potent selective force on males: males whose physical or behavioral traits are preferred get to mate.

life span

the maximum age to which members of a species can live.

Age specific life expectancy (Ex)

the mean amount of time an individual of age x is expected to live

genetic similarity

the measure of the proportion of alleles shared by two populations

fundamental niche

the niche in the absence of competition

dispersal

the one-way movement of an individual from the natal area. the natal area, the place that the organism was born, is by definition a good place for the species. There are mortality costs with dispersal. Travel through unknown terrain leads to increased predation risk. Burrows, nests, caught food, etc. are not available during the dispersal. In some cases, dispersal occurs because economically important resources such as food or nest sites are in short supply. If the population density is high enough , competition precludes access to critical resources --> individuals who cant access these resources disperse despite the costs of doing so.

social system

the organization of a group of individuals in terms of group size and composition, cooperation among individuals, and the mating system. All three ultimately result from evolution of behaviors. Group size and composition: vary widely and exemplify the principle of optimization. over time we expect selection to optimize group size relative to the ecological situation and prey base. Solitary behavior: reasons: Prey can be subdued by one individual. Their prey is relatively less abundant so that even the large home ranges of these species can support just a single individual. --> short term pair bonds. some of the group living species exhibit a degree of cooperation. --> altruistic behaviors.

home range

the portion of the habitat used by an individual on a daily or seasonal basis. may shift overtime due to competition from other individuals or changes in the habitat.

coefficient of inbreeding

the probability that two alleles in an individual are identical by descent.

Fisher's Fundamental Theorem

the rate at which the mean fitness of a population increases by natural selection is equal to the additive genetic variation in fitness additive genetic variation is the summed phenotypic eggects of the avatiaon within the gene pool. Additive genetic variation is the combined effects of all the different genes that affect a trait. the intensity of selection also influences whether an ecotype will arise --> a direct result of the ecological conditions.

diffuse competition

the summed effects of all competitors

pleiotropic effects

three important hypothesis used to explain senescene: The concept of reproductive value is critical to these. 1. Intensity of natural selection declines with age. Occurs because of the shape of the Vx curve. Genes whose effects occur after the peak of the Vx curve are not subject to the same intensity that would be felt if the Vx curve was higher. Specifically, deleterious mutuations accumulate and only begin to take effect after reproductive value = 0 or is not large. 2. Pleiotropic effects: The action of single gene that affects several phenotypic traits. Genes that benefit younger individuals whose reproductive value is high will be selected for even if they have deleterious pleitropic effects that occur in old age. 3. Limiting Soma theory: limiting resources devoted to reproduction result in decreased somatic maintenance. --> leads to cell death and senescene.