Unit_9_objectives.doc

Unit 9 objectives: C generalist feeders, because they have a wider diet, need to learn which foods are safe to eat and how to aquire such foods This learning process, or cultural information, is passed down in this case, as apposed to through specialists, because the transmission of information is not done through genes that guide the organisms preference, but by conspecifics Mating types: Promiscuous: no strong pair bonds or lasting relationships Monogamous: mates remain together for a longer period with one mate; species male and female are morphologically very similar Beneficial because male can help protect new borns and have more viable offspring Most birds are monogamous than mammals because they are less sure of their children?s offspring Polygamous: an individual of one sex mating with several of the other, again for a long period of time Polygyny: system where a single male has a relationship with many females; males and females are usually dimorphic, with males being howier and often larger than females If their young can help themselves after they are born, it makes more sense for the male to leave his young and seek another female with which he can reproduce In cases with mammals such as lions where males serve a protective purpose, Polygyny may exist in the form of a few lions with a harem of females Polyandry: a single female mates with several males; males and females are dimorphic, but females are showier Agnostic Behavior: an often ritualized contest that determines which competitor gains access to a resource, such as food or mates Occurs when Males compete for mates as a source of sexual selection that can reduce variation among males On the arts quad, two dogs will display the intensity of their motivation. The dog that appears to be the most intent on winning will most likely put the other dog into submission just by virtue of his intense display (barred teeth, flat hair, growling) The submissive dog will lie down and expose it?s stomach (its most vulnerable area) Game Theory: evaluates alternative strategies in situations where the outcome depens on the strategies of all individuals involved Consider the male side-blotched lizard: males can have orange, blue or yellow throats Each throat color is associate with a different pattern of behavior Orange throat males are the most aggressive and defend large territories that contain many females Blue males are also territorial but defend smaller territories and fewer females Yellow throats are nonterritorial males that mimic females and use sneaky tactics to gain the chance to mate Each type is equipped to stop one, but not the other from mating with their females, which causes a cycle of changing frequencies of each male Game theory provides a way to think about complex evolutionary problems in which relative performance, not absolute performance, is the key to understanding the evolution of behavior Relative Fitness: the contribution an individual makes to the gene pool of the next genration, relative to the contributions of other individuals in the population Inclusive Fitness: the total effect an individual has on proliferating its gnees by producing its own offspring and by proiding aid that enables other close relatives, who share many of those genes, to produce offspring ? gives reason for altruistic behavior Altruism: some animals behave in ways that reduce their individual fitness but increase the fitness of other individuals in the population (1) Hamilton?s Rule and Kin Selection: H?s rule: three key variables in act of altruism: benefit to recipient, cost to altruist and coefficient of relatedness C = how many fewer offspring altruist produces B = average number of extra offspring that the beneficiary of altruistic act produces C.O.R: r= equals the fraction of genes that on average are shared Rule: rB>C is when natural selection favors altruism Kin Selection: the natural selection that favors altruistic behavior by enhancing reproductive success of relatives Weakens with hereditary distance (siblings have r = .5 but aunt and niece, r = .25 and first cousins, r = .125 (2) Reciprocal Altruism: exchange of aid between related or non-related individuals that is commonly invoked to explain altruism that occurs between unrelated humans it?s rare in other animals, though it appears in the ?tit-for-tat strategy? See above Sociobiology: The main premise is that certain behavioral characteristics exist because they are expressions of genes that have been perpetuated by natural selection Populaition Density: the number of individuals per unit area or volume Population Dispersion: the pattern of spacing among individuals within the boundaries of the population Method of measureing: Mark-Recapture Method Scientists capture a random sample of individuals in a population Tag/mark each individual and then release it Whiel this first group mixes back into pupolaiton, a second sample is captured The number of marked animals recaptured in the second sampling (n) should equal the number of individuals amrked and relased in the first sampling (m) divided by the estimated population size (N) - N = mn/x or x/n = m/N Assumption is that the marked and unmarked animals have the same probability of being captured, that marked have mixed completely back into opulation and that no individuals are born, die, immigrate, or emigrate during the resampling interval Patterns of dispersion: Clumped: association of orgamisms in tight, small groups Many animals, such as sea stars, group together where food is abundant Also may group like this for mating purposes Uniform: evenly spaced patter of dispersion Results from antagonistic social interactions such as territoriality Birds neting on small islands such as king penguins on South Georgia island in South atlantic ocean exhbiti uniform spacing, maintained by aggressive intractions between neighbors Random: many plants, such as dandelions, grow from windblown seeds that land at random and later germinate Survivorship Curve: a plot of the proportion or numbers in a chort still alive at each age (based on information in a Life Table) Type I: curve is flat at start, relecting low death rates during early and middle life, and then drops steeply as death rates increase among older age groups Offspring that produce few offspring, but which care for them often have this type of curve Type II: intermediate, with a constant death rate over the organisms life span This type of survivorship exists in Belding?s ground squirrels and other rodents, various inverts and some lizards Type III: drops sharply at the start, reflecting very high death rates for young, but flattens out as death rates decline for those few individuals that survive the early period of die-off Associated w/ organisms that produce a lot of offspring but provide little or no care, such as long-lived plants, many fishes and most marine invertebrates Many species fall somewhere between these curves, or express a ?stair-stepped? curve Life History: made up of the traits that affect an organism?s schedule of reproduction and survival (from birth, through reproduction, to death Three basic variables: when reproduction begins, how often organism reproduces and how many offspring are produced during each reproductive episode Where survival rate of young is low Semiplarity: ?one-shot? pattern of big bang reproduction; female will produce a very large amount of offspring in the hopes that some of them at least will survive (salmon are an example) Iteroparity: repeated reproduction; production of a few large eggs during secdon year of life and then reproduce annually for several years Can actually protect their young Favored in dependable environments, where animals are more likely to survive reproduction and reproduce again (some lizards ? egg example from above) * time, energy and nutrients limit the reproductive capabilities of all organisms Study of red deer in Scotland showed that females that reproduced in a given summer were more likely to die during the next winter than females that did not reproduce Trade-off exist between reproduction and Survival Trade off also: if a parent can create many offspring, expects them to fend for themselves (can?t take care of them all) but if it only produces a few, needs to protect them to ensure that it?s genes are passed on (maintain its physical fitness) Fecundity (essentially fertility in relation to the number of offspring produced) Producing large numbers of offspring v. small numbers: large numbers allow for the parent to abandon their young, assuming that at least some will survive, but may expend more effort reproducing to such a degree (examples: animals that suffer high predation rates (highly preyed upon) such as quail, sardines and mice, tend to produce large numbers of offspring Primates are examples of animals with small numbers of offspring, live in environments High current fecundity v. survival and future fecundity Current fecundity means that the animal will at present produce more offspring and spread it?s genes Survival and future fecundity means that the animal (such as the red deer in Scotland) will have a better chance of survival if it does not immediately reproduce B) Carrying Capacity: (symbolized as K) the maximum population size that a particular environment can sustain - If individuals cannot obtain sufficient resources to reproduce, per capita birth rate (b) will decline - If they cannot consume enough energy to maitntain themselves, or if disease or parasitism increases with density, (d) may increase - Each instance (or both combined) results in a lower (r) K Selection: selection for life history traits that are sensitive to population density (density dependent selection) r selection: selection for life history traits that maximize reproductive success in un-crowded environments (low densities) ( density independent selection C generalist feeders, because they have a wider diet, need to learn which foods are safe to eat and how to aquire such foods This learning process, or cultural information, is passed down in this case, as apposed to through specialists, because the transmission of information is not done through genes that guide the organisms preference, but by conspecifics Mating types: Promiscuous: no strong pair bonds or lasting relationships Monogamous: mates remain together for a longer period with one mate; species male and female are morphologically very similar Beneficial because male can help protect new borns and have more viable offspring Most birds are monogamous than mammals because they are less sure of their children?s offspring Polygamous: an individual of one sex mating with several of the other, again for a long period of time Polygyny: system where a single male has a relationship with many females; males and females are usually dimorphic, with males being howier and often larger than females If their young can help themselves after they are born, it makes more sense for the male to leave his young and seek another female with which he can reproduce In cases with mammals such as lions where males serve a protective purpose, Polygyny may exist in the form of a few lions with a harem of females Polyandry: a single female mates with several males; males and females are dimorphic, but females are showier Agnostic Behavior: an often ritualized contest that determines which competitor gains access to a resource, such as food or mates Occurs when Males compete for mates as a source of sexual selection that can reduce variation among males On the arts quad, two dogs will display the intensity of their motivation. The dog that appears to be the most intent on winning will most likely put the other dog into submission just by virtue of his intense display (barred teeth, flat hair, growling) The submissive dog will lie down and expose it?s stomach (its most vulnerable area) Game Theory: evaluates alternative strategies in situations where the outcome depens on the strategies of all individuals involved Consider the male side-blotched lizard: males can have orange, blue or yellow throats Each throat color is associate with a different pattern of behavior Orange throat males are the most aggressive and defend large territories that contain many females Blue males are also territorial but defend smaller territories and fewer females Yellow throats are nonterritorial males that mimic females and use sneaky tactics to gain the chance to mate Each type is equipped to stop one, but not the other from mating with their females, which causes a cycle of changing frequencies of each male Game theory provides a way to think about complex evolutionary problems in which relative performance, not absolute performance, is the key to understanding the evolution of behavior Relative Fitness: the contribution an individual makes to the gene pool of the next genration, relative to the contributions of other individuals in the population Inclusive Fitness: the total effect an individual has on proliferating its gnees by producing its own offspring and by proiding aid that enables other close relatives, who share many of those genes, to produce offspring ? gives reason for altruistic behavior Altruism: some animals behave in ways that reduce their individual fitness but increase the fitness of other individuals in the population (1) Hamilton?s Rule and Kin Selection: H?s rule: three key variables in act of altruism: benefit to recipient, cost to altruist and coefficient of relatedness C = how many fewer offspring altruist produces B = average number of extra offspring that the beneficiary of altruistic act produces C.O.R: r= equals the fraction of genes that on average are shared Rule: rB>C is when natural selection favors altruism Kin Selection: the natural selection that favors altruistic behavior by enhancing reproductive success of relatives Weakens with hereditary distance (siblings have r = .5 but aunt and niece, r = .25 and first cousins, r = .125 (2) Reciprocal Altruism: exchange of aid between related or non-related individuals that is commonly invoked to explain altruism that occurs between unrelated humans it?s rare in other animals, though it appears in the ?tit-for-tat strategy? See above Sociobiology: The main premise is that certain behavioral characteristics exist because they are expressions of genes that have been perpetuated by natural selection Populaition Density: the number of individuals per unit area or volume Population Dispersion: the pattern of spacing among individuals within the boundaries of the population Method of measureing: Mark-Recapture Method Scientists capture a random sample of individuals in a population Tag/mark each individual and then release it Whiel this first group mixes back into pupolaiton, a second sample is captured The number of marked animals recaptured in the second sampling (n) should equal the number of individuals amrked and relased in the first sampling (m) divided by the estimated population size (N) - N = mn/x or x/n = m/N Assumption is that the marked and unmarked animals have the same probability of being captured, that marked have mixed completely back into opulation and that no individuals are born, die, immigrate, or emigrate during the resampling interval Patterns of dispersion: Clumped: association of orgamisms in tight, small groups Many animals, such as sea stars, group together where food is abundant Also may group like this for mating purposes Uniform: evenly spaced patter of dispersion Results from antagonistic social interactions such as territoriality Birds neting on small islands such as king penguins on South Georgia island in South atlantic ocean exhbiti uniform spacing, maintained by aggressive intractions between neighbors Random: many plants, such as dandelions, grow from windblown seeds that land at random and later germinate Survivorship Curve: a plot of the proportion or numbers in a chort still alive at each age (based on information in a Life Table) Type I: curve is flat at start, relecting low death rates during early and middle life, and then drops steeply as death rates increase among older age groups Offspring that produce few offspring, but which care for them often have this type of curve Type II: intermediate, with a constant death rate over the organisms life span This type of survivorship exists in Belding?s ground squirrels and other rodents, various inverts and some lizards Type III: drops sharply at the start, reflecting very high death rates for young, but flattens out as death rates decline for those few individuals that survive the early period of die-off Associated w/ organisms that produce a lot of offspring but provide little or no care, such as long-lived plants, many fishes and most marine invertebrates Many species fall somewhere between these curves, or express a ?stair-stepped? curve Life History: made up of the traits that affect an organism?s schedule of reproduction and survival (from birth, through reproduction, to death Three basic variables: when reproduction begins, how often organism reproduces and how many offspring are produced during each reproductive episode Where survival rate of young is low Semiplarity: ?one-shot? pattern of big bang reproduction; female will produce a very large amount of offspring in the hopes that some of them at least will survive (salmon are an example) Iteroparity: repeated reproduction; production of a few large eggs during secdon year of life and then reproduce annually for several years Can actually protect their young Favored in dependable environments, where animals are more likely to survive reproduction and reproduce again (some lizards ? egg example from above) * time, energy and nutrients limit the reproductive capabilities of all organisms Study of red deer in Scotland showed that females that reproduced in a given summer were more likely to die during the next winter than females that did not reproduce Trade-off exist between reproduction and Survival Trade off also: if a parent can create many offspring, expects them to fend for themselves (can?t take care of them all) but if it only produces a few, needs to protect them to ensure that it?s genes are passed on (maintain its physical fitness) Fecundity (essentially fertility in relation to the number of offspring produced) Producing large numbers of offspring v. small numbers: large numbers allow for the parent to abandon their young, assuming that at least some will survive, but may expend more effort reproducing to such a degree (examples: animals that suffer high predation rates (highly preyed upon) such as quail, sardines and mice, tend to produce large numbers of offspring Primates are examples of animals with small numbers of offspring, live in environments High current fecundity v. survival and future fecundity Current fecundity means that the animal will at present produce more offspring and spread it?s genes Survival and future fecundity means that the animal (such as the red deer in Scotland) will have a better chance of survival if it does not immediately reproduce B) Carrying Capacity: (symbolized as K) the maximum population size that a particular environment can sustain - If individuals cannot obtain sufficient resources to reproduce, per capita birth rate (b) will decline - If they cannot consume enough energy to maitntain themselves, or if disease or parasitism increases with density, (d) may increase - Each instance (or both combined) results in a lower (r) K Selection: selection for life history traits that are sensitive to population density (density dependent selection) r selection: selection for life history traits that maximize reproductive success in un-crowded environments (low densities) ( density independent selection