TEST BANK for Animal Behavior, 11th Edition by Dustin R, John Alcock, Linda Green, Paul Nolan.

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 1: An Introduction to Animal Behavior Multiple Choice 1. “If female lizards with reddish throats produce more eggs than females with orangish throats, then the reddish throat is an evolved adaptation.” This statement a. is true, because this species has variation, a critical requirement for the evolution of adaptations by natural selection. b. is false, because females with orangish throats could still have more offspring that live to reproduce than females with reddish throats. c. is false, because there is no guarantee that females with reddish throats are the best for the long-term preservation of this species. d. could be true or false, because we cannot tell without knowing whether reddish females outnumber orangish females in this species.

Answer: b 2. The statement “Lemmings disperse from areas of high population density because they inherited this ability from a lemming-like ancestor in the past” is a hypothesis about a. evolved function. b. evolutionary history. c. genetics and development. d. adaptive value.

Answer: b 3. The theory of plate tectonics (which explains the current and past positions of the continents in terms of the movements of huge geologic plates on Earth’s surface) is called a theory because it a. has been shown via repeated tests to be true. b. is an explanation that is potentially falsifiable. c. is an explanation that can be applied widely, to every continent, past and present. d. is an explanation that needs to be tested.

Answer: c 4. In order for Darwinian natural selection to cause evolutionary change, a population must contain individuals that differ hereditarily in some characteristic because a. in a population without this kind of variation, the species is doomed to extinction. b. when all individuals have the same genes, then all individuals are exactly alike in all respects. c. uniform populations are evolutionary dead ends.

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d. unless there is variation of this sort, parents cannot pass on their advantageous attributes to their offspring.

Answer: d 5. We observe variation in a population of lizard with respect to how fast individuals can run. We attempt to select for the ability to run slowly, not quickly. After six generations of selective breeding of only the slowest with the slowest, the mean running speed of the lizards has not changed. What is the appropriate scientific conclusion based on this work? a. After six generations of artificial selection, the frequency of slow runners in the population has remained unchanged. b. After six generations of artificial selection, the frequency of slow runners in the population has increased. c. The differences between the lizards in running speed in the original population were not caused by genetic differences among them. d. The results are invalid because the researchers failed to maintain enough variation in running speed in their selected lineage, so evolutionary change was impossible.

Answer: c 6. We observe a frog that carries its babies on its back away from where the eggs hatched. Below are two questions about this observation: X. Does the frog do this to move the babies to a place where they will be safer?

Y. Why does the frog expend time and energy moving its offspring from the place where they were “born”?

Which of the two is a true causal question? a. X, because this is the more specific of the two questions b. X, because we can test this idea but not the idea presented in Y c. Y, because this statement tells what we should expect to find in nature d. Y, because it is not a hypothesis itself but could be answered by a hypothesis Answer: d 7. It makes sense to separate the results of an experiment from the scientific conclusion of a research project because a. the data were collected not as an end in and of themselves but to help evaluate a hypothesis. b. the scientific conclusion should refer to what ought to have been collected in the way of data, not the actual data themselves. c. the dictionary defines scientific conclusion as “a proven result,” and the results of an experiment are rarely completely certain. d. it is good to keep all the experimental items, the design of the experiment, the methods used, the expected results, and the actual collected data in one single category.

Answer: a 8. Which is an example of a Darwinian puzzle? a. Salmon can smell a few molecules of chemicals in the stream in which they were born.

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b. Adult birds scream in pain when caught by a predator. c. If two or even three eggs are added to a bird’s nest, the adult birds often can rear them successfully along with their own chicks. d. Bats can catch moths in complete darkness thanks to their ability to hear echoes from their own cries.

Answer: c Questions 9–12.

Consider the following observation: Male song sparrows sing more at dawn than during any other time the day.

9. Males sing to provide accurate information to mates about their physical condition.

This is an example of a. a causal question. b. a prediction. c. test evidence. d. a scientific conclusion.

Answer: d 10. Males that receive a “care package” of extra food the day before should produce more songs during the dawn hour than those that do not receive supplemental food. This is an example of a. a causal question. b. a prediction. c. test evidence. d. a scientific conclusion.

Answer: b 11. What is the evolved function of the pattern of song production by the song sparrow?

This is an example of a. a causal question. b. a prediction. c. test evidence. d. a scientific conclusion.

Answer: a 12. If an adaptation is the product of natural selection, the trait will a. provide a net reproductive gain for individuals that possess the attribute. b. raise the reproductive success of individuals more than any other alternative that has appeared in the species over evolutionary time. c. enhance the survival of the fittest individuals in the species. d. help preserve the species as a whole against the risk of extinction.

Answer: b 13. Contest resolution that is mediated by harmless, non-contact threat displays is a Darwinian puzzle because

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a. the winners of these interactions have nevertheless expended time and energy asserting control of certain resources that they could use if they win. b. the winners of these interactions would benefit from injuring or killing those competitors that would again return to challenge them for key resources. c. the losers of these interactions concede defeat without actual fighting and thereby may prematurely give up resources that would raise their fitness. d. the losers’ refusal to fight strips the species of the means by which it could remove excess individuals from the population.

Answer: c 14. Deceptive signaling is widespread in nature. For example, certain orchids luring pollinator wasps to them with flower petals that smell like receptive female wasps. This case is a Darwinian puzzle because a. the proportion of orchid flowers that set fruit as result of successful pollination is low. b. natural selection ought to favor discriminating behavior on the part of male wasps so that they do not waste time, energy, and even sperm on orchid flowers. c. time and energy spent on orchids reduces the capacity of the wasp population to grow, since the deceptive plants slow the ability of male wasps to fertilize all the eggs of their females. d. it is unknown why orchid flowers evolved to smell like the females of certain wasps.

Answer: b 15. In what way does the theory of descent with modification differ from the theory of evolution by natural selection? a. Organisms can evolve even if natural selection is not responsible for the changes that occur. b. Descent with modification applies only to large animals and plants and not to smaller organisms, like bacteria and protozoans. c. The theory of descent with modification is designed to explain why organisms have evolved adaptations, whereas natural selection explains why organisms can persist unchanged over long periods of evolutionary time. d. Descent with modification provides an account of the evolutionary events that took place as a modern species evolved from ancestral ones; natural selection theory provides a means for why some changes spread through a species while others did not.

Answer: d 16. Although some male crab spiders find and mate with adult female crab spiders, others that find immature females remain with them even though the subadult females are incapable of mating until they become adults. This behavior is a Darwinian puzzle because a. the genetic basis for this behavior is difficult to establish with clarity. b. mating is instinctive in spiders and therefore all males should behave the same way; either mating with adult females exclusively or guarding subadult females exclusively.

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c. males that guard subadult females cannot use the time to find receptive mature females. d. evolutionary biologists would argue that subadult female spiders should not interfere with the ability of males to find mature females.

Answer: c 17. Male monogamy is a Darwinian puzzle because a. females could benefit from receiving sperm and assistance from more than one male. b. polygynous males generally have access to more eggs to fertilize than monogamous males. c. females that mate with just one male have offspring with lower genetic diversity than the offspring of polyandrous females, which harms the species as a whole. d. although sexual selection favors monogamy in males, natural selection does not.

Answer: b 18. Workers in honey bees and other eusocial insects are considered Darwinian puzzles because a. these workers are largely sterile and so should be eliminated over time by natural selection. b. Darwin felt that the self-sacrificing behavior of these insects could not be explained by the theory of group selection. c. the self-sacrificing workers do not live as long as the queens of the same species of eusocial insects. d. queens with a large worker force produce more reproductive sons and daughters than those with a small worker force.

Answer: a

Short Answer 19. Select a behavioral trait that has been discussed in class, and describe a plausible evolutionary scenario for how that trait was produced, incorporating the three conditions (or tenets) of the theory of natural selection.

Answer: Answers will vary with traits, but they should describe variation in the trait, identify heritable component(s) of that variation, and then describe a selective advantage for survival and/or reproduction that would increase the frequency of the trait in the population.

20. What are the proximate and ultimate explanations for the adaptive value of a male langur’s harming the offspring of females in his group?

Answer: The infanticide hypothesis describes a proximate cause: promotion of ovulation in the female langurs, which increases reproductive opportunity for the male langur. The ultimate explanation would point toward a higher number of offspring by a male who engages in infanticide compared with a male that joins a new group but does not kill any existing offspring.

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21. Refer to the figure below.

The graph displays the impact of gull behavior on crows foraging for chicken eggs (mock gull eggs) that were placed outside, on the border, or inside the gull colony. Do the data below support the predator distraction hypothesis?

Answer: Yes, the data demonstrate that with decreasing distance to the gull colony, the mock gull eggs are protected with increased gull mobbing behavior (red). This results in lower predation rates on the eggs (blue).

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Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 2: The Integrative Study of Behavior

Multiple Choice 1. I say that a white-crowned sparrow sings a distinctive dialect because its genes influenced how its song system was assembled, which in turn made dialect learning possible. You say that it sings the song because of the operation of the robust nucleus of the arcopallium, which sends signals to the bird’s vocal control apparatus, the syrinx.

Who is correct? a. I am wrong because learning is environmentally determined, not determined by the bird’s genes. b. You are wrong because the bird’s vocal apparatus is called the larynx, not the syrinx. c. We both may be right because our two hypotheses offer two different proximate levels of analysis of dialect singing. d. We both may be right because our two hypotheses offer two complementary levels of analysis, one proximate and the other ultimate.

Answer: c 2. Research results showed that in zebra finches, the sonograms of the songs of a father and his sons reveal a close match unless a son has been deafened early in life. Someone says that the causal question underlying this research was “Do zebra finches acquire their song by learning?” This statement is _______ because _______. a. incorrect; the work was really done to establish that the songs were instinctive b. incorrect; the question is actually a hypothesis, not a causal question c. correct; zebra finches do learn their songs, as clearly shown by the sonograms d. correct; by learning their songs from their fathers, males are likely to sing a song attractive to females Answer: b 3. White-crowned sparrows evolved from an ancestral species that possessed the capacity for song learning. This is an example of a. a developmental explanation. b. a physiological explanation. c. an adaptive value explanation. d. an explanation relating to evolutionary history.

Answer: d 4. It is difficult for a sparrow to learn a dialect, which enables females to mate with only those males with good dialects so as to increase the song competence of their offspring.

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This is an example of a. a developmental explanation. b. a physiological explanation. c. an adaptive value explanation. d. an explanation relating to evolutionary history.

Answer: c 5. Males in different populations have different forms of certain genes that influence the development of the song system. This is an example of a. a developmental explanation. b. a physiological explanation. c. an adaptive value explanation. d. an explanation relating to evolutionary history.

Answer: a 6. The ability to sing the local dialect enables a bird to communicate more effectively with neighboring males. This is an example of a. a developmental explanation. b. a physiological explanation. c. an adaptive value explanation. d. an explanation relating to evolutionary history.

Answer: c 7. Males in different populations are exposed to different songs, an experience that influences the kind of song that the birds learn. This is an example of a. a developmental explanation. b. a physiological explanation. c. an adaptive value explanation. d. an explanation relating to evolutionary history.

Answer: a 8. The differences among dialects are environmentally determined, not genetically controlled. This is an example of a. a developmental explanation. b. a physiological explanation. c. an adaptive value explanation. d. an explanation relating to evolutionary history.

Answer: a 9. Males in different populations have song systems in their brains that operate slightly differently. This is an example of a. a developmental explanation. b. a physiological explanation. c. an adaptive value explanation. d. an explanation relating to evolutionary history.

Answer: b

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10. Young adult white-crowned sparrows are motivated to match their song as closely as possible to that of their neighbors. This is an example of a. a developmental explanation. b. a physiological explanation. c. an adaptive value explanation. d. an explanation relating to evolutionary history.

Answer: b

Short Answer Questions 11−15.

Young white-crowned sparrows are remarkably good at remembering the sounds produced by adult white-crowned males singing around them. If the learning abilities of these birds evolved by Darwinian natural selection, specific conditions must have applied to the species in the past.

Determine whether each of the following statements about those conditions is correct or incorrect.

11. There must have been variation in the memory skills of individuals.

Answer: correct 12. The sparrow species must have been threatened by extinction at some point.

Answer: incorrect 13. Better than average song “rememberers” must have been able to pass on their abilities to their offspring.

Answer: correct 14. Better than average song “rememberers” must have had more surviving offspring on average than the typical sparrow at that time.

Answer: correct 15. Any changes that took place in the past must have promoted greater population stability in this bird.

Answer: incorrect 16. Refer to the figure below.

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What is the proposed reasoning in Nowicki et al. 2002 for why the experimental group displayed lower values for each of the data sets? (Note: The birds in the experimental group were given 30 percent less food than the birds in the control group.)

Answer: The experimental birds suffered from lower nutritional quality and higher developmental stress, which resulted in reduced song complexity and reduced brain development of the HVC. Questions 17–18.

Researchers produced three sonograms from male zebra finches: a father and two sons.

One of the sons had been deafened early in life. The intact young male’s song exactly matched that of his father; the deafened male produced a rudimentary sub-song.

17. Why were these sonograms made? What aspect of the scientific process are they related to?

Answer: The sonograms constituted test evidence, data, from an experiment designed to determine the effects of early deafening on male song learning; the results enabled the researchers to conclude that the learning process involved the male bird’s ability to hear himself and his father sing.

18. Outline the complete scientific process for which the sonograms are only one part.

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Answer: The experiment must have been initially imagined as part of a prediction: “If we do an experiment in which we deafen a young male, it will not be able to hear itself sing and thus should not be able acquire a good copy of its father’s song.” This prediction must have been derived from a hypothesis: “Zebra finch males must be able to hear themselves sing (or hear their fathers sing) if they are to eventually come to sing their father’s song.” This hypothesis must have been developed in response to a causal question: “In the zebra finch, why do sons tend to sing like their fathers?”

19. There are several hypothesized benefits to a bird that can sing the local dialect.

Describe two hypotheses that explain the adaptive benefit of learning to sing from one’s neighbor.

Answer: The adaptive hypotheses explain the acoustic, social, and/or ecological benefit to learning one’s song from the local environment. The hypotheses are the following: environmental adaptation hypothesis, recognition hypothesis, information-sharing hypothesis, sexual selection hypothesis, and geographic matching hypothesis.

20. In cooperatively breeding birds, songs provide information about the group as well as individual identity, whereas birds with smaller breeding groups (most often composed of only kin) have songs that provide group identity without individual distinction. Why? Answer: According to the information-sharing hypothesis, species with larger breeding groups have expanded repertoires of calls to interpret information about kin and social groupings. If a species has small breeding groups that are almost always kin, all individuals learn the “family” call and utilize it to recognize the group. In larger groups of kin and non-kin, individual birds learn both their natal songs and additional calls as they join with other birds.

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Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 3: The Developmental and Genetic Bases of Behavior

Multiple Choice 1. When someone says that there is a gene for a behavior, they most likely mean that a. the gene is solely responsible for the development of that behavior. b. individuals with different forms of that gene exhibit different behaviors. c. the role of the environment in affecting the development of the behavior is relatively small. d. the behavior is unlikely to respond to selection, since there is no variation in the species.

Answer: b 2. Is an adaptation a “genetically determined” phenotype? Why or why not? a. No, because the development of every phenotype requires more than genetic information. b. No, because adaptations are only revealed when individuals interact with the environment. c. No, because half of every phenotype is composed of genes, while the other half is environmental. d. Yes, because only hereditary traits can enable an individual to adapt to changing conditions.

Answer: a 3. Could social and solitary phenotypes ever occur in the same species strictly because of environmental differences that affected the development of the two phenotypes? a. No, because both genetic and environmental factors are necessary for development of every phenotype. b. No, because this is equivalent to saying that the two traits are environmentally determined, which is incorrect. c. Yes, because as identical twins illustrate, some differences in gene–environment interactions are caused only by differences in the environment side of the interaction. d. Yes, because the environment is absolutely essential for the development of every phenotype, especially behavioral ones.

Answer: c 4. The proximate significance of the fact that artificial selection often leads to change in a tested population is that it a. demonstrates that genetic differences are often responsible for phenotypic differences among the members of a population. b. shows that populations often possess the potential for evolutionary change in the present, and so they could have been evolving in the past. c. demonstrates that the environment has relatively little effect on the development of most behavioral attributes.

d. shows that most animal species have a long way to go in reaching their full evolutionary potential.

Answer: a 5. The ultimate significance of the fact that artificial selection often leads to change in the tested population is that it a. demonstrates that genetic differences are often responsible for phenotypic differences among the members of a population. b. shows that populations often possess the potential for evolutionary change in the present, and so they could have been evolving in the past. c. demonstrates that the environment has relatively little effect on the development of most behavioral attributes. d. shows that most animal species have a long way to go in reaching their full evolutionary potential.

Answer: b 6. Gene knockout experiments (in which a particular gene is deactivated) have been carried out to a. show that animal behavior is dependent upon genetic information. b. create two categories of individuals that differ with respect to a single gene. c. test whether a given behavior controlled by that gene contributes to the reproductive success of individuals. d. demonstrate that DNA is the molecule of heredity.

Answer: b 7. If an experimenter is able to select for increased barking in a population of domesticated dogs over four generations, then a. there must have been genetic variation relevant to the development of barking in the initial population in the experiment. b. barking is probably very important to the reproductive success of dogs. c. we have proof that natural selection and domestication are somewhat different. d. the experimenter has shown that if dogs were to return to the wild, the population would evolve toward a higher level of barking in nature as well.

Answer: a 8. Garter snakes only recently invaded California and have evolved the ability to eat slugs since that recent invasion. This provides confirmation that a. evolution acts to expand the diets of animals to buffer the species against changes in food supply that might lead to the extinction of the species. b. the early slug-eating garter snakes must have reproduced less on average than those that lacked this ability in the early populations in California. c. every slug-eating garter snake had higher reproductive success than all the slug-rejecting snakes generation after generation, until there were no more slug-rejecters in California. d. None of the above Answer: d

Short Answer 9. Refer to the figure below.

The presence of older forager bees inhibits the development of younger bees into foragers.

Explain how the data below support or refute this hypothesis, and state the proximate explanation for this phenomenon.

Answer: These experimental data show that the resident nurse bees developed into foragers when young bees were added to the colony, but they did not undergo early transition to foragers when older bees were added to the colony. Foragers produce ethyl oleate in their digestive crop and pass some of this chemical in the nectar back to bees in the hive.

10. Describe an experiment to test whether there is a genetic component for the difference in slug consumption by coastal versus inland garter snakes, Thamnophis elegans. Base the experiment on the results depicted below.

Answer: To identify the genetic component of slug eating, we could genetically cross a parental population of inland snakes that do not feed upon slugs with a parental population of coastal snakes that readily feed upon slugs. We would then isolate each offspring at birth and test the offspring for slug-eating preferences. If slug aversion has a genetic basis, then this phenotype should be observed across many offspring, potentially in varying levels. If slug aversion is environmentally determined, then all the offspring should be equally likely to consume slugs. It would be important to compare the eating preferences of the offspring by using a control food source, such as frog or rodent, to identify if slug-eating preferences were distinct.

Questions 11–12.

The killdeer employs a distraction display in which it spreads a wing conspicuously and moves off, as if injured. This display occurs only when a killdeer is approached by a potential predator while the bird is incubating eggs and not when the killdeer is approached by a large mammal.

11. “The killdeer’s creative responses are the result of its ability to use conscious thought to solve its problems in nest defense.” What is this statement called? Explain.

Answer: This is a hypothesis, as it explains the killdeer’s creative responses as the result of the bird’s ability to think consciously through the problems it faces.

12. “The proximate mechanisms underlying killdeer conscious thought spread over time because individuals with these proximate abilities were able to better cope with novel fitness-threatening situations.” Is this an accurate statement? Explain.

Answer: This is an accurate statement that integrates proximate and ultimate explanations for the killdeer’s apparently insightful behavior.

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 4: The Neural Basis of Behavior Multiple Choice 1. Stimulus filtering is an adaptation in the star-nosed mole because a. this property of its nervous system helps the mole population secure the energy base on which the species depends. b. individuals vary hereditarily in the way in which the mole’s cerebral cortex analyzes sensory inputs from the animal’s nose. c. individuals that ignore some categories of potential sensory inputs forage on worms more effectively than they would otherwise. d. some star-nosed moles leave more copies of their genes to the next generation than others.

Answer: c Questions 2−4.

Refer to the figure below.

2. Which sound frequency (kHz) are the male flies most sensitive to? a. 2 b. 5

c. 10 d. 20 Answer: c 3. The reaction of the female fly to sounds of _______ kHz best illustrates the concept of stimulus filtering. a. 2 b. 5 c. 10 d. 20 Answer: a 4. If the data collected for the graph were not gathered simply to describe the hearing abilities of the fly, then (for the biologists who did the research) the graph constitutes a a. hypothesis on why the fly species has been able to survive to the present. b. test of a prediction on fly hearing ability, based on the kind of sound frequencies produced by crickets. c. check on the prediction that crickets should have evolved the ability to avoid their fly parasites. d. test of the hypothesis that fly hearing abilities are designed to help the species maintain a stable or growing population.

Answer: b Questions 5–7.

Refer to the figure below.

5. The “intensity threshold” on the graph refers to the a. loudest sound of a given sound frequency that a cricket can hear. b. softest sound of a given sound frequency that a cricket can hear. c. most intense response given by a cricket to a given sound frequency. d. least intense response given by a cricket to a given sound frequency.

Answer: b 6. Crickets can most easily hear sound frequencies of _______ kHz. a. 3 b. 5 c. 20 d. 40 Answer: b 7. The graph does not constitute a scientific conclusion primarily because a. it does not contain the prediction that the data were designed to check. b. it does not answer a causal question. c. the data were collected from only one cricket and thus are inconclusive. d. the data were gathered to test whether a prediction was correct prior to reaching a conclusion.

Answer: d 8. To determine whether a circadian rhythm operated under endogenous control versus regulation via an environmental stimulus, it would be necessary to a. find the gene or genes that were involved in the circadian rhythm mechanism. b. demonstrate the animal exhibited normal variation in its activities over 24-hour periods. c. destroy the circadian rhythm mechanism to demonstrate its importance in regulating the schedule of the animal. d. show that the circadian rhythm mechanism could operate even in a constant environment.

Answer: d 9. The behavior described is a. genetically determined. b. learned as the bee matures and interacts with females. c. the product of an interaction between the bee’s genes and its environment. d. not a fixed action pattern.

Answer: c 10. Why is the change in sensitivity of female midshipman fish to the “songs” produced by males of their species a proximate example of stimulus filtering? a. In the seasons when female midshipman fish lack a sensitivity to high frequency elements they cannot easily detect the sounds that they are able to hear in the summer. b. These changes in sensitivity are linked to the genetically determined innate releasing mechanisms of the fish. c. The changes in sensitivity to high frequency sounds occur when it is adaptive for females to hear the songs of males eager to spawn with females. d. The greater sensitivity to high frequency sounds enables females to hear sounds that require a different proximate mechanism than the mechanism that enables females to hear lower frequency sound.

Answer: a

11. You could demonstrate that a particular circadian rhythm is adaptive for a given cricket species by a. showing that a rhythm is maintained even when the crickets are placed in an experimental set up in which they never experience darkness. b. showing that the crickets are capable of entrainment in which environmental cues are used to set its biological clock each day. c. showing that the experimental inactivation of the optic lobes of the crickets abolish their circadian rhythm. d. finding related species of the cricket species in question, those that exhibit different circadian rhythms that can be linked to environmental differences among the different species.

Answer: d Questions 12–13.

Mike May studied the relationship between cricket behavior and the ultrasonic cries of bats.

12. Which statement constitutes a hypothesis? a. He noticed that the hindwing farther from the source of the ultrasound didn’t make a stroke as deep as the other hindwing of the insect. b. He found that with every burst of ultrasound, the wings of the cricket seemed to stop. c. He asked himself, was this symbiosis another mechanism that enabled the cricket to turn away from the ultrasound produced by a bat? d. He proposed that if the wing farther from the ultrasound did not make a full stroke, it should produce less thrust—inducing a turn toward that side.

Answer: c 13. Which statement constitutes a prediction? a. He noticed that the hindwing farther from the source of the ultrasound didn’t make a stroke as deep as the other hindwing of the insect. b. He found that with every burst of ultrasound, the wings of the cricket seemed to stop. c. He asked himself, was this symbiosis another mechanism that enabled the cricket to turn away from the ultrasound produced by a bat? d. He proposed that if the wing farther from the ultrasound did not make a full stroke, it should produce less thrust—inducing a turn toward that side.

Answer: d

Short Answer 14. Why would some bird chicks, such as those from estrildid finch species, have elaborate markings inside their throats? Explain the proximate and ultimate cause of the markings.

Answer: The markings are a sign stimulus to the parent’s innate behavior to place food in the mouth of the chick. They are hypothesized to exist as a deterrent to brood parasitism.

15. Despite the lack of brain-controlled neural circuitry, a male praying mantis that has suffered decapitation by a female rotates his body in a circular pattern until encountering the female’s

body and then aligns himself with her body to commence copulation. What is the selective advantage of this?

Answer: The female may consume the male’s head while still being receptive to copulation.

There is a clear fitness advantage to males that are capable of this behavior prior to their imminent death.

16. The brain’s somatosensory cortex does not consist of neurons that relay information equally from all parts of the animal’s body. Describe an example of this by identifying a focal animal and the body parts that are disproportionately high in neuron input to the somatosensory cortex.

Answer: Examples from text may include human, star-nosed mole, naked mole rat, eastern mole, masked shrew, and East African hedgehog. The sensory structures key for that animal in its environment are overrepresented in the somatosensory cortex (eyes, hands, nose, whiskers, mouth).

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 5: The Physiological Basis of Behavior

Multiple Choice 1. John Wingfield and his coauthors made the following statement early in their article on testosterone and the challenge hypothesis: “The prevailing ‘challenge’ hypothesis asserts that testosterone and aggression correlate only during periods of heightened interactions between males.” This statement is a a. definition of the challenge hypothesis. b. prediction derived from the challenge hypothesis. c. statement about the evidence that supports the challenge hypothesis. d. scientific conclusion.

Answer: b 2. The naked mole rat lacks a circadian rhythm of activity. The ultimate adaptive significance of this point is that a. because naked mole rats live underground, they are not exposed to daily changes in light intensity and thus have no cues for the entrainment of a circadian rhythm. b. the environment of the naked mole rat is such that queens and kings gain no reproductive advantage by having a sterile work force that is active on a 24-hour schedule. c. naked mole rats are primitive mammals that do not have the sophisticated mechanisms that control circadian rhythms. d. naked mole rats do not have the genetic information that would enable them to develop a brain capable of circadian rhythms.

Answer: b Questions 3−4.

Refer to the figure below.

3. What does “LL” stand for? a. 12 hours of light b. 24 hours of light c. 25.5 hours of light d. Low light, as in dusk conditions Answer: b 4. The most significant feature of this record for persons studying circadian rhythms is the a. demonstration that this species has a 24-hour circadian rhythm. b. absence of a circadian rhythm under the special conditions of the experiment. c. randomness in the time at which daily activity began. d. persistence of an activity period in the absence of daily environmental cues.

Answer: d 5. Testosterone is apparently a very costly hormone for males to produce and use. Why, then, has natural selection resulted in the males of some many species investing in the production and use of this hormone? a. Because natural selection cannot override the effects of shared ancestry; because male animals share a common ancestor that used testosterone adaptively, they continue to do so today.

b. Because testosterone helps insure that males will be motivated to search for and to find all the receptive females of their species, thereby increasing the odds that the females will all be able to produce some offspring. c. Because under a variety of circumstances, the hormone makes is possible for males to be either aggressive or sexually motivated in ways that increase individual genetic success. d. Because males that are able to pay the price for producing and using testosterone are demonstrating that they are able to overcome this handicap, which means that they are genetically worthy members of the breeding stock for their population.

Answer: c 6. A statement about the “challenge hypothesis” (in which male birds become aggressive only when their control of a territory is challenged by another individual) asserts that testosterone concentrations in the blood and male aggression should correlate most tightly during periods of heightened interactions between males. This statement is primarily a a. definition of the challenge hypothesis. b. prediction derived from the challenge hypothesis. c. statement about the evidence that supports the challenge hypothesis. d. scientific conclusion.

Answer: b 7. What is a photoperiod? a. The duration of light in 24 hours b. The period of light in 12-hour intervals c. The increase in light over a series of 24-hour periods d. The variation in light that occurs during daytime Answer: a

Short Answer 8. Apply the reproductive readiness hypothesis to explain why some songbirds are able to respond to environmental conditions suitable for raising offspring, even when the conditions are presented outside of the traditional breeding season. What is the ultimate explanation for the birds’ response?

Answer: Some songbird species have been observed to maintain high levels of LH hormone throughout the year, which results in gonads that are relatively ready for action whenever the birds are exposed to good rain and food availability. The RR hypothesis asserts that this persists because it gives a fitness advantage in unpredictable environments.

9. The occurrence of heightened chronic stress can cause an individual to produce and continue to release stress hormones, such as glucocorticoids, that eventually damage the affected individual’s immune system. Why has such an obviously costly response evolved?

Answer: Perhaps because under brief stress a hormonal response is beneficial in that the hormone prepares the animal’s body to cope with stress in the “expectation” that negative conditions will not last long. But when, in rare cases, stressful conditions persist, the continued release of stress

hormones has a damaging effect. On average, stress hormones raise the fitness of the individual even though occasionally they have the opposite effect

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 6: Avoiding Predators and Finding Food

Multiple Choice Questions 1–5.

In the evening, males of a species of bee (Idiomelissodes duplocincta) form sleeping clusters in which dozens or hundreds of bees perch close together overnight. An assassin bug kills bees at these sleeping sites, but usually only one or two bees per night. (A) The bees do not join forces to fight the bug when one appears, so it may be that a bee joins the cluster to dilute the risk that it will be one of the unlucky ones killed at random. (B) The same sort of clustering of defenseless prey occurs in spadefoot frog tadpoles; hundreds of tadpoles swim and feed together in pools containing carnivorous water beetles that attack and kill them. (C) In contrast, males of other bees in the genus Idiomelissodes are larger and more capable of deterring a predator on their own, and they sleep apart. (D) The dilution effect hypothesis receives support from the observation that males of certain poisonous inedible flies do not form sleeping groups.

1. How many hypotheses were tested implicitly or explicitly by the researcher who wrote the paragraph? a. 1 b. 2 c. 3 d. 4 Answer: b 2. Which sentence in the paragraph contains an example of divergent evolution? a. A b. B c. C d. D Answer: c 3. Which sentence in the paragraph contains an example of convergent evolution? a. A b. B c. C d. D Answer: b 4. Which sentence in the paragraph illustrates an improper use of the comparative method?

a. A b. B c. C d. D Answer: d 5. Sentence B is a. a causal question. b. a hypothesis. c. a prediction. d. test evidence.

Answer: d 6. If a foraging tactic is “optimal,” this behavior a. helps to maintain the population at a level likely to promote the long-term survival of the species. b. supplies a fitness benefit to individuals. c. is an efficient way to collect food. d. confers more fitness on individuals than any other alternative trait in the population.

Answer: d Questions 7–9.

Refer to the figure below.

The figure shows a matrix of fitness payoffs for interactions between two behaviorally different types of gulls: those that always fish for themselves and those that sometimes steal fish from others. P stands for the baseline fitness that a gull derives when it fishes for itself. B is the fitness gained by a thief when it steals a fish from a fish-for-self type. C is the fitness cost associated with an attempt to steal a prey.

7. What causal question is the model designed to answer? a. How can a hereditary thief phenotype spread in a population of fish-for-self types? b. What are the fitness costs and fitness benefits of fish-for-self versus thief phenotypes? c. When can group selection cause evolutionary change to take place? d. What are the circumstances under which maladaptive traits can take over a population?

Answer: a

8. What is the significance of the fact that in a population composed entirely of thieves, the average fitness payoff for a thief is P – C, whereas in a population composed entirely of fish-forself types, the average payoff is P? a. It tells us that fish-for-self types will become more common over time. b. It tells us that the spread of a trait depends not on its absolute fitness effect but rather on its fitness effect relative to an alternative trait. c. It tells us that the thief phenotype is an evolutionarily maladaptive trait. d. It tells us that the thief phenotype is costly for the population as a whole.

Answer: b 9. If B were greater than C, the solitary phenotype would a. perpetuate itself but not increase over time. b. increase steadily over time. c. disappear from the population over time. d. increase until it made up 50 percent of the population.

Answer: c 10. You read that a foraging tactic is “optimal” only if it is the most efficient way of acquiring calories from the environment. This is _______ because _______. a. true; this will enable the species to grow and avoid extinction b. true; selection favors traits that have large benefits c. false; species that collect food too efficiently run the risk of destroying the resource base needed for that species d. false; sometimes animals gain more fitness by sacrificing some foraging efficiency in order to better avoid predators Answer: d 11. A conditional strategy is unquestionably an adaptation when individuals able to switch tactics a. leave some surviving descendants to carry their genes into the next generation. b. leave more surviving offspring than individuals with any other available strategy. c. are better able to adjust to changing conditions than other members of their species. d. experience a net gain in fitness from their behavioral flexibility.

Answer: b Questions 12–14.

For each of the following situations, which theory is most likely to be used by a behavioral biologist who is formulating a hypothesis?

12. A seed-eating bird forages solitarily. This is an example of a. game theory. b. optimality theory. c. group selection theory. d. conditional strategy theory.

Answer: b

13. A seed-eating bird forages in groups with competitive companions. This is an example of a. game theory. b. optimality theory. c. group selection theory. d. conditional strategy theory.

Answer: a 14. Smaller seed-eating birds select smaller seeds than larger seed-eating birds do. This is an example of a. game theory. b. optimality theory. c. group selection theory. d. conditional strategy theory.

Answer: d 15. A certain fish-eating hawk that lives by large lakes can capture more pounds of fish per unit time if it were to hunt farther from shore instead of staying close to the shoreline. The hawk, however, does stay close to the shoreline. This demonstrates that a. natural selection theory is probably not applicable in this case. b. optimal foraging theory is probably not applicable in this case. c. an optimal foraging hypothesis based on maximizing caloric intake alone is probably incorrect in this case. d. the fish species found close to the shoreline in large lakes are more nutritious than those in the center.

Answer: c 16. If a population is subject to frequency-dependent selection, then a. two alternative forms of a trait can persist indefinitely in the population. b. the rarer of two forms of a trait will become somewhat rarer in the next generation. c. the frequency of an adaptation will become greater over time, depending on the extent to which individuals with that trait outreproduce individuals with the alternative attribute. d. neither form of the trait is considered an adaptation but instead these forms are kept in the species to provide flexibility, should the environment change.

Answer: a

Short Answer Questions 17–21.

Observation: You observe “shaky leaf walking” in a video of a Madagascaran mantid (one of about 1,800 species, a member of one of dozens of genera of mantids, which constitute one of eight families of mantids).

Hypothesis: The behavior is effective as camouflage because it makes the mantid look like a dried leaf blown about on the leaf litter of the forest floor or a trembling leaf on a low-lying shrub.

17. State a prediction from this hypothesis that could be tested via additional observation.

Answer: (Answers will vary.) The mantid should be the size and shape of dried leaves in its actual habitat.

18. State a prediction that could be tested via an experiment.

Answer: (Answers will vary.) In experiments with caged insect-eating birds, individual mantids placed on the appropriate background should take much longer to find than those placed on a nonleafy substrate.

19. State a prediction that could be tested via the comparative method. (Use a legitimate example of the comparative method based on the phenomenon of convergent evolution.)

Answer: (Answers will vary.) The shaky leaf walking trait should appear in two or more families of mantids separated phylogenetically by other families whose members do not exhibit the trait; the several families in which shaky walking appeared independently should share similar ecological pressures, such as living on leaf litter and having predators that hunt visually.

20. State a prediction that could be tested via the comparative method. (Use a legitimate example of the comparative method based on the phenomenon of divergent evolution.)

Answer: (Answers will vary.) Closely related mantids in the same family that do not share similar ecological pressures should exhibit different modes of walking, with shaky walking restricted to leaf-based habitats, while species that habitually search for prey on tree trunks or at flowers should not walk in this manner.

21. State a prediction that illustrates illegitimate use of the comparative method. After stating your prediction briefly, explain why this prediction would not be accepted by many behavioral biologists.

Answer: (Answers will vary.) The shaky walking trait should be present only in camouflaged, leaf-like mantids that are hunted by birds and live in areas where the background matches their appearance. This prediction fails to recognize that cases in which two or more closely related species share the same trait as a result of a recent shared ancestor do not constitute powerful comparative support for hypotheses on the adaptive value of a given trait. Shared ancestry as a cause for similar traits is not the same as the independent evolution of the trait in response to a particular ecological pressure via convergent evolution. The mantids in question may have retained a particular trait from a common ancestor, which provides an explanation in terms of evolutionary history rather than adaptive value, per se.

22. Several hundred male bees will sometimes gather in the evening to sleep on the dried stems of a shrub. A predatory assassin bug sometimes visits the bees and kills some as they are settling down. Present three hypotheses on the possible adaptive, antipredator value of these sleeping aggregations. For each hypothesis, present a piece of evidence that would enable you to reject the hypothesis.

Answer:

Hypothesis 1. The improved vigilance hypothesis: More bees = more eyes = sooner detection of bug = faster dispersal of bees from danger. Evidence that rejects hypothesis: The bees do not disperse after settling down to sleep even when some of their fellow bees are under attack.

Hypothesis 2. The selfish herd hypothesis: The bees aggregate in order to use other individuals as living shields behind which to hide. Evidence that rejects hypothesis: The bees do not jostle or compete for the safer central positions within the group.

Hypothesis 3. The dilution-effect hypothesis: The bees aggregate in order to lower the risk of being unlucky victims of the assassin bug on a given evening. Evidence that rejects hypothesis: Larger sleeping groups attract proportionately more predators, so that the risk of dying is the same no matter what the size of the group.

Questions 23–24.

In the “Finding Food” episode of his series Trials of Life, Sir David Attenborough features a hummingbird species that feeds almost exclusively on the nectar of the Heliconia flower. He explains that each hummingbird has a circuit that takes it from one plant to another, with the bird arriving regularly at a given flower after a set period. It could take 30 minutes, more or less, to complete the round trip.

23. In one sentence, explain why the following statement could be wrong: “The bird is behaving optimally because it is getting enough energy to continue making its foraging circuit.”

Answer: Because an optimal forager maximizes its fitness as a result of its behavioral decisions, merely taking in enough calories to survive may not be optimal, particularly if there are factors other than caloric intake that affect a forager’s fitness.

24. The hummingbird does not immediately insert its beak into many Heliconia flowers but hesitates before approaching the flowers more closely. How might this hesitation still be consistent with at least one optimal foraging hypothesis? (Consider the different factors that might contribute to true optimality.)

Answer: If optimality involves a consideration of the risks facing a forager, then a hesitation that permitted the hummingbird to check a flower for hidden predators, especially bird-eating snakes, might enhance the individual’s fitness even while decreasing the rate of nectar intake.

Alternatively, if by checking the flower the hummingbird was able to better position its bill within the flower, an increase in pre-insertion time might lead to more efficient removal of the flower’s nectar.

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 7: Territoriality and Migration

Multiple Choice Questions 1−5.

Refer to the figure below.

The figure shows flight energetics in great white pelicans that are gliding by themselves, flapping by themselves, or traveling in a group V-formation.

1. What is the mean wingbeat frequency (in wingbeats per minute) of a pelican leading the Vformation? a. 45 b. 60 c. 90 d. 105

Answer: c 2. The graph represents a. a hypothesis. b. a prediction. c. test evidence. d. a scientific conclusion.

Answer: c 3. This work would be based on optimality theory if the a. researchers expected that pelicans would, when possible, minimize their flight expenses. b. fitness benefit derived from flying in a V-formation exceeded the cost of the behavior. c. researchers had tested the prediction that other large, flock-forming species would also fly in V-formations under some conditions. d. researchers believed that every aspect of pelican behavior was an adaptation, that is, an ideal solution to an environmental problem of some sort.

Answer: a 4. “The birds in front of the V are expected to be low-ranking birds that are unable to displace physically superior rivals from the more energy-saving positions in the formation.” This statement is a a. hypothesis. b. prediction. c. test. d. scientific conclusion.

Answer: b 5. The finding that both great white pelicans and brown pelicans fly in V-formation is an example of a. convergent evolution. b. divergent evolution. c. the comparative method. d. the effects of shared ancestry.

Answer: d 6. If the distribution of individuals over a set of habitats is consistent with ideal free distribution theory, then a. the fitness of individuals in different habitats will be the same. b. some habitats will attract territorial individuals, while others will not. c. the mean survival time of individuals in the different habitats will be different. d. the areas associated with higher fitness will be occupied after habitats linked to lower fitness.

Answer: a 7. A conditional strategy is unquestionably an adaptation when individuals able to switch tactics a. leave some surviving descendants to carry their genes into the next generation. b. leave more surviving offspring than individuals using any other behavioral strategy.

c. are better able to adjust to changing conditions than are other members of their species. d. experience a net gain in fitness from their behavioral flexibility.

Answer: b 8. A bird occupies a territory in which there are abundant food sources but also high levels of predation. This is an example of a. payoff asymmetry. b. ideal free distribution. c. economic defensibility. d. resource holding potential.

Answer: c 9. If two housecats are introduced into a new home, the one that is brought in a day or two before the other will more strongly defend the space as its territory. This illustrates a. the dear enemy effect. b. the payoff asymmetry hypothesis. c. the new home’s economic defensibility. d. the first cat’s underestimation of its resource holding potential.

Answer: b 10. While studying a species of firefly, you notice that the territories they occupy are constant across the breeding season, even though you observe multiple territorial disputes. Once territories are established, you do not observe a single case of a territory changing ownership.

This finding supports the a. dear enemy effect. b. payoff asymmetry hypothesis. c. resource holding potential hypothesis. d. arbitrary contest resolution hypothesis.

Answer: d 11. Male American redstarts (a small species of warbler) that are in the best physical condition typically are found in the species’ preferred habitat. Individuals in worse condition tend to be found in scrubby, secondary growth. This statement supports the a. dear enemy effect. b. payoff asymmetry hypothesis. c. resource holding potential hypothesis. d. arbitrary contest resolution hypothesis.

Answer: c

Short Answer 12. Explain the similarities and differences between dispersal and migration.

Answer: Migration involves annual movement away from and subsequent return to the same location. Dispersal is a permanent move from one location to another. Both can be costly because individuals have to secure extra energy for their travels (energetic costs), they run the

risk of falling prey to predators in the unfamiliar area through which they are moving (risk costs), and while they are moving they cannot invest time in other activities (time costs).

13. When is being adaptable selectively disadvantageous?

Answer: When individuals that have the capacity for flexible responses gain benefits that are not greater than the costs imposed by this capacity, such as the cost of maintaining the extra neural tissue that makes behavioral flexibility possible.

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 8: Principles of Communication

Multiple Choice 1. If a trait has adaptive value, the trait a. enables individuals to adapt to changing environments. b. confers a reproductive advantage on individuals. c. has spread because of group selection. d. increases the life span of individuals.

Answer: b Questions 2–4.

A spider researcher, Pia Stålhandske, knew that males of Pisaura mirabilis offer their mates a nuptial gift—a prey item, such as a cricket—whose acceptance by the female is critical for male mating success. Males wrap their generally dark-colored food gifts in white silk. Stålhandske wondered if the males wrapped their gifts to make them look like the white, silk-covered egg sacs that mated females make and protect by holding them in their jaws until the spiderlings hatch.

2. The last sentence in the paragraph above constitutes a. a causal question. b. a hypothesis. c. a prediction. d. test evidence.

Answer: b 3. What theory was Stålhandske using to explore this species’ courtship behavior? a. Sensory exploitation b. Ritualization c. Signal d. Descent with modification Answer: a 4. Which of the following predictions might Stålhandske have felt could be correct, given her presumption that males might be making their nuptial gifts look like egg sacs? a. The time for a female to accept a nuptial gift should be less for prey covered in silk that has been experimentally colored brown instead of white. b. Natural silk-covered prey should not be comparable in light reflectance to silken egg sacs.

c. Females should be prepared to accept silken egg sacs that had been taken from them and offered back as if they were nuptial gifts. d. Males that offer nuptial gifts should be larger than males that fail to do so.

Answer: c 5. White-tailed deer raise their tails when they spot a predator approaching; the predator typically gives up its pursuit once it knows that the faster prey species has seen it. This is an example of a. cueing. b. eavesdropping. c. honest signaling. d. deceitful signaling.

Answer: c 6. The American kestrel is a small falcon that is occasionally taken as prey by larger birds. It has two large spots on the back of its head that somewhat resemble large eyes. This is an example of a. cueing. b. eavesdropping. c. honest signaling. d. deceitful signaling.

Answer: d 7. Both the sender and receiver of a signal benefit from the transfer of information. This is an example of a. cueing. b. eavesdropping. c. honest signaling. d. deceitful signaling.

Answer: c 8. The sender of a signal benefits from the transfer of information but the receiver does not. This is an example of a. cueing. b. eavesdropping. c. honest signaling. d. deceitful signaling.

Answer: d

Short Answer 9. What information is communicated through the waggle dance of the honeybee? Give a plausible hypothesis for the origin of this behavior.

Answer: The bee conveys both the distance and the compass direction to the food source. The dance may have evolved from pre-existing behavior that was crucial in nest-finding, or it may have evolved incrementally in previous lineages that developed mechanisms to share information about nectar quality, direction, and distance.

10. Refer to the figure below.

Each data point on the graph represents a population of guppies. What can be inferred from the data concerning the female guppies’ interest in orange foods and the male guppies’ orange coloring? State a hypothesis for why males are orange.

Answer: The foraging preference for orange foods varies between populations, and the female preference for orange males is correlated with the strength of the preference for orange foods.

Hypotheis: Males evolved orange coloring to exploit females’ pre-existing bias for orange.

11. Elaborate male traits that are used in mate choice of birds in a given species B are entirely absent in distantly related sister taxon, C. The last common ancestor of these birds, species A, also had males that were elaborately decorated. Which is more likely to have evolved first in species B, the male trait or the female preference?

Answer: The male trait may have been lost and regained while these populations evolved into multiple species. In these cases, it is likely that female-preference traits remain strong and persist through the divergence of species.

12. In animal communication, why does it benefit a sender to use honest signaling for body size and shape?

Answer: The sender who relies on honest signaling can minimize negative encounters with individuals of higher and lower rank. In the absence of signaling, an individual needs to interact directly with others to determine rank, introducing opportunity to become injured or sick.

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 9: Reproductive Behavior

Multiple Choice 1. The incubation of eggs by a male starling is an example of a. male–male competition sexual selection. b. female choice sexual selection. c. male parental investment. d. female parental investment.

Answer: c 2. The attack of a fellow female’s eggs by a female starling is an example of a. male–male competition sexual selection. b. female choice sexual selection. c. male parental investment. d. female parental investment.

Answer: d 3. The tusk of the male narwhal is an example of a. male–male competition sexual selection. b. female choice sexual selection. c. male parental investment. d. female parental investment.

Answer: a 4. The presentation of a diamond ring to a woman by her husband-to-be is an example of a. male–male competition sexual selection. b. female choice sexual selection. c. male parental investment. d. female parental investment.

Answer: b 5. The transfer of large quantities of sperm to a polyandrous female fruit fly by a male is an example of a. male–male competition sexual selection. b. female choice sexual selection. c. male parental investment. d. female parental investment.

Answer: b

Questions 6−9.

Refer to the figure below.

P stands for “parental,” and the other letters represent animal species. Species V and Y are the only ones that exhibit male parental care; the others are exclusively maternal care species. There are several ancestral species, of which A is basal.

6. Which species lived longest ago? a. A b. B c. C d. D Answer: a 7. Which species has given rise to exactly four living descendant species? a. A b. B c. C d. D Answer: b 8. Which two species illustrate one case of divergent evolution? a. V and Y b. W and X c. W and Z d. Y and Z Answer: d 9. Which pair of species illustrates a case of convergent evolution? a. V and W

b. V and Y c. W and X d. Y and Z Answer: b 10. Persons studying male bluegill (a type of fish) reproductive behavior have discovered three different methods of male reproduction: territoriality, sneaking, and satellite behavior. We hypothesize that these long-standing differences are hereditary. Which of the following predictions would follow from this hypothesis? a. Sneaking males should have sneaking sons. b. The reproductive success of the three types must be different. c. The environment should have no effect on the development of sneaking behavior. d. The presence of satellite males should lower the fitness of those females whose eggs they fertilize.

Answer: a 11. If we hypothesize that the behavioral differences among bluegill (a type of fish) males are the product of a conditional strategy, which of the following predictions would follow from this hypothesis? a. Territorial males should have territorial sons. b. The reproductive success of the three types could be different. c. The environment should have no effect on the development of satellite behavior. d. The presence of satellites should increase the fitness of those females whose eggs they fertilize.

Answer: b Questions 12−13.

Males of the marine isopod Paracerceis sculpta come in three sizes: large alphas, medium betas, and small gammas. When the average fitness of each type was measured, researchers found that there were no statistically significant differences among the three types.

12. This finding constitutes test evidence because the data a. were gathered to check a prediction from a conditional strategy hypothesis only. b. prove that the conditional strategy hypothesis is correct for this species. c. were gathered to check a prediction from a three-strategies hypothesis only. d. were gathered to check predictions from both conditional strategy and three-strategies hypotheses.

Answer: d 13. The lack of a fitness difference between the three male phenotypes suggests that the behavioral differences among them are hereditary because a. all phenotypes are 50 percent genetic and 50 percent environmental. b. the three phenotypes are three adaptations maintained because of their equal fitness effects. c. the three phenotypes appear to be three tactics controlled by a single conditional strategy. d. the three phenotypes have to be hereditary if they are to help the species improve over time.

Answer: b

14. Why might male Mormon crickets have a lower potential reproductive rate than females? a. Because they make relatively few sperm, compared to the egg production rate of females. b. Because males compete so intensely for mates that this shortens their lifespan. c. Because males donate a very large, hard-to-replace spermatophore to each mate. d. Because females make almost no parental investment in their offspring.

Answer: c

Short Answer Questions 15−18.

In the narwhal, females live in groups and males have an elongate tooth (a tusk). We hypothesize that the tusk is a functional weapon that has evolved by sexual selection and enables males with the biggest weapon to be polygynous. We wish to test this version if sexual selection via the comparative method. Determine whether each of the following predictions represents (a) a legitimate use or (b) an illegitimate use of the comparative method.

15. Males of the beluga, the narwhal’s closest relatives, should also use their teeth in clashes over access to females.

Answer: illegitimate 16. The bodies of male narwhals should be marked by scars of the sort that could be produced by narwhal tusks.

Answer: illegitimate 17. In the warthog, a wild pig species in which females live in small bands, the males should have much larger protruding tusks than the females.

Answer: legitimate 18. In a giant scarab beetle, males with the largest rhinoceros-like horns should be more likely to be polygynous than those with smaller horns.

Answer: legitimate Questions 19–21.

Prior to class, go to the Web of Science or the Internet to locate the paper by C. D. MacLeod titled “Intraspecific scarring in odontocete cetaceans: an indicator of male ‘quality’ in aggressive social interactions?”

19. From the references, provide a complete, correct citation for a paper by Hobson and Martin on another whale species.

Answer: Hobson R. P., Martin A. R. 1996. Behaviour and dive times of Arnoux’s beaked whales, Berardius arnuxii, at narrow leads in fast ice. Canadian Journal of Zoology 74 (2): 388–393.

20. Based on information in the abstract of MacLeod’s paper, make a prediction about the diet of the beluga, a very close relative of the narwhal, but one that has many teeth, not just one.

Answer: If the beluga and narwhal have diverged in their diets, as seems likely from their different teeth arrangements, then perhaps the belugas will not eat squid and jellyfish but instead will focus on more difficult-to-grasp prey, such as fish.

21. Based on information in the abstract of MacLeod’s paper, make a prediction about which sex of the beaked whales (Family: Ziphiidae) should have enlarged teeth if these species have evolved convergently with the narwhal.

Answer: If the narwhal’s tusk is the product of sexual selection for success in male aggressive combat, then the beaks of the beaked whales, which are not close relatives of the narwhal, should also be restricted to males.

Questions 22–26.

For each of the following traits, designate PI if the trait is an example of parental investment and NO if the trait cannot be categorized as parental investment.

22. The donation by a mother elephant seal of special nutrients and biochemicals other than DNA to her eggs Answer: PI 23. A female starling’s destruction of the eggs laid by another female that has mated with the first female’s partner (because a male starling with only one mate will help her incubate the eggs) Answer: PI 24. The elaborate ornaments that a male bird of paradise possesses, without which he will not attract a mate Answer: NO 25. The transfer of large quantities of sperm to a female, which increases the probability that one of these sperm will fertilize the eggs Answer: NO 26. The production and transfer of chemicals (in a male ejaculate) to a female fruit fly that increase the probability that the sperm transferred to her at the same time will fertilize her eggs Answer: NO

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 10: Mating Systems

Multiple Choice 1. Sexual selection differs from natural selection in that a. the traits under sexual selection can be environmentally influenced, unlike those that are the product of natural selection. b. hereditary differences among phenotypes are required for natural selection to occur, but not for sexual selection to occur. c. sexual selection can produce traits that harm the survival of the species, whereas natural selection acts to preserve the species over the long term. d. natural selection affects a broader spectrum of traits than sexual selection, which acts only on individual differences in the ability to gain access to mates.

Answer: d Questions 2−3.

Females of a species of fly form swarms in which several dozen individuals gather together to fly about in circles. When a male enters the swarm, females inflate their abdomens and move toward the male, who carefully selects one of the many females as his partner.

2. What is there about this species that constitutes a Darwinian puzzle? a. The means by which females manage to enlarge their abdomen, which requires a special and still-mysterious abdomen-inflating device b. The fact that the members of one sex have evolved a truly bizarre display to induce the opposite sex to mate with them c. The fact that females have to persuade apparently choosy males to mate with them d. The fact that many females have to wait for a mate, which reduces the reproductive potential of the species Answer: c 3. Which is an example of a group selectionist puzzle? a. The means by which females manage to enlarge their abdomen, which requires a special and still-mysterious abdomen-inflating device b. The fact that the members of one sex have evolved a truly bizarre display to induce the opposite sex to mate with them c. The fact that females have to persuade apparently choosy males to mate with them d. The fact that many females have to wait for a mate, which reduces the reproductive potential of the species Answer: d

Questions 5−9.

Kirk’s dik-dik is a small African antelope that usually forms male–female pairs.

4. Is it possible that monogamy evolved in this species because males are attempting to guard their partners from other males? This is an example of a. a hypothesis. b. a prediction. c. test evidence. d. a scientific conclusion.

Answer: a 5. Males place their scent marks over those of the female, which hides the signals of sexual receptivity that females produce when they are fertile. This is an example of a. a hypothesis. b. a prediction. c. test evidence. d. a scientific conclusion.

Answer: c 6. It may be that if males were experimentally removed from pairs, females would wander from their territories into the territories of other males. This is an example of a. a hypothesis. b. a prediction. c. test evidence. d. a scientific conclusion.

Answer: b 7. If DNA data were collected from the offspring of intact pairs, it should be found that the offspring of the females were sired by their social partners.

Hypothesis This is an example of a. a hypothesis. b. a prediction. c. test evidence. d. a scientific conclusion.

Answer: b 8. It is also possible that pairs form in order to protect their offspring, with two adults doing a better job of protection than just one. This is an example of a. a hypothesis. b. a prediction. c. test evidence. d. a scientific conclusion.

Answer: a 9. Genetic monogamy is

a. extremely rare. b. the rule (with a few exceptions) among mammals, but not among birds. c. the rule (with a few exceptions) among birds, but not among mammals. d. never found in reptiles.

Answer: a 10. Male ostriches guard a nest into which a female lays an egg from their mating. The next day she mates with a different male; the first male also mates with a different female, which places her egg in his nest. This species exhibits a. polygynandry. b. polyandry. c. monogamy. d. polygyny.

Answer: a 11. If you study a pair of European beavers, you will find that all of the young in their colony are genetic offspring of the pair. This species exhibits a. polygynandry. b. polyandry. c. monogamy. d. polygyny.

Answer: c 12. Long-term storage of sperm in some species of tortoise allows a female to produce a clutch of eggs with offspring fathered by multiple males. This species exhibits a. polygynandry. b. polyandry. c. monogamy. d. polygyny.

Answer: b 13. Red deer males compete to control access to an entire herd of does, meaning that a single male will mate with multiple females, while other males have zero fitness. This species exhibits a. polygynandry. b. polyandry. c. monogamy. d. polygyny.

Answer: d

Short Answer 14. Give the primary reason that monogamy in male animals would be considered a Darwinian puzzle.

Answer: Males generally have sufficient sperm to fertilize a great many eggs, which ought to favor males that mate with a great many egg producers.

15. Polyandry in females might be advantageous if polyandrous females were to secure some genes from their partners that were especially compatible with the genes in their eggs. State a prediction that follows from this hypothesis.

Answer: (Answers may vary.) In order to expand the potential gene pool, the mating partners of females will vary substantially from female to female.

16. Why have behavioral ecologists concluded that the ecology of females has more to say about the evolution of the mating system of a species than the ecology of males?

Answer: Receptive females are usually in short supply, not the other way around.

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 11: Parental Care

Multiple Choice 1. In what sense is the male hangingfly’s gift of a fly to his mate rather like parental investment, even if the female does not use the fly to help her produce larger or better eggs? a. The time and energy spent capturing the gift reduce the male’s potential reproductive output. b. The gift may be used to increase the number of eggs the female produces. c. The gift makes it more likely that that male will have offspring in the future. d. The consumption of the fly means the female may live longer, just as parental investment results in parents living longer.

Answer: a 2. The Trivers-Willard hypothesis primarily attempts to explain a. variation in the sex ratio of offspring. b. parent-offspring conflict. c. siblicide and infanticide. d. the decline in reproductive output with age.

Answer: a 3. Ghalambor and Martin (2001) found that a North American species of thrush placed higher value on their nest full of offspring than did a similar South American species. This differential response is due to a. a more abundant food supply in North America. b. South American birds generally living longer than those in North America. c. South American birds generally laying only one egg per nest. d. higher parasitism rates in North America.

Answer: b 4. Why do birds make a good group for the study of parental care? a. They don’t lactate. b. They are found on every continent. c. Both sexes are able to provide for their young. d. They don’t discriminate against their offspring.

Answer: c

Short Answer

Questions 5−6.

Bright red inner mouths in chicks indicate the level of carotenoid pigments in the chicks’ diets.

5. How does the signal of quality hypothesis explain why parents might feed these chicks more than their paler-mouthed siblings?

Answer: Carotenoids are associated with strong immune system function, and chicks with brighter red coloring suggest an individual with a healthier body and higher survival potential. If the red coloring is genetic and not dietary, we might hypothesize that parents use the red coloring to identify offspring from brood parasites. Other reasonable hypotheses: signal of good genes/strong development.

6. Assume that the red mouth coloring is hereditary, not dietary; what might be a different ultimate explanation for why parents preferentially feed red-mouthed chicks?

Answer: If the red coloring is genetic and not dietary, we might hypothesize that parents use the red coloring to identify offspring from brood parasites. Other reasonable hypotheses: signal of good genes/strong development.

7. Explain the parent-offspring conflict in siblicide behavior of great egrets. In species such as the Nazca booby, why do females lay a second egg if they tolerate high siblicide rates?

Answer: In siblicide, the surviving sibling gains greater access to food resources from the parent, but the parent’s reproductive value decreases. In species that tolerate high levels of siblicide, experiments suggest that the second egg is still laid as reproductive insurance against hatching failure.

8. Is parental care more likely in birds with high adult mortality or low adult mortality? Why is this the case, and what evidence can you provide to support your answer?

Answer: In birds with high adult mortality (such as in North American species), parents are more likely to invest in current offspring with high levels of parental care, as the likelihood of subsequent clutches is small. In birds with low adult mortality (such as in South American species), parents are more likely to have low parental care because they will have future reproductive events.

9. Refer to the figure below.

In the figure above, it is hypothesized that egg guarding evolved in treehoppers three times (labelled 1, 2, and 3). Imagine if the trait actually appeared in the ancestral population at the base of the tree, labelled Membracinae. What is the minimum number of trait changes that would be necessary to produce the presence of egg guarding depicted in the tree?

Answer: Four. A loss in the branches leading to: Hypsoprorini, Membracini, and Bolbonota, and a gain in the branch leading to Leioscyta.

10. When is male parental care more likely to evolve?

Answer: When there is a high cost to female fecundity if she provides parental care for her offspring.

11. Why are parent birds more likely to be able to discriminate among chicks and find their own offspring (often with 80 percent or higher accuracy) in social species compared to solitary nesters?

Answer: There is little chance of making a mistake in solitary nests, so there is little to no selective pressure for signals that assist parent-offspring recognition. In communal nesting birds, the offspring have evolved more complex vocalizations that enable parents to identify their offspring.

12. Rough-winged swallows will adopt the offspring of other swallows when parents are experimentally given these nestlings, just as lesser kestrels do when nesting on rooftops. This kind of similarity has a label; what is it, and why might these two species behave similarly?

Answer: This is probably a case of convergent evolution in which an absence of offspring recognition has been maintained because of the rarity (until very recently) with which parents of the two unrelated species were confronted with the possibility of caring for someone else’s offspring.

Questions 13–16.

The lesser kestrel is a hawk that nests in colonies. In this species, young birds sometimes move to the nests of adults that aren’t their parents, perhaps because their parents are failing to rear them properly. Researchers found the following: • The adopted nest-switching nestlings are not in poorer condition than those that stay in their natal nest.

• The adopted nestlings are not fed at a higher rate than they had been prior to the switch.

• The adoptees do not become top dogs in the dominance hierarchy among chicks in the new nest.

13. These data were collected to test a hypothesis. What is likely to have been that hypothesis?

Was it proximate or ultimate?

Answer: The ultimate hypothesis was that nestlings moved to acquire more resources from their foster parents than they would get from their actual parents.

14. What conclusion did the researchers reach?

Answer: The fitness-benefiting hypothesis was incorrect.

15. What relevance do you attach to the information that the lesser kestrel once nested on small cliff ledges but now often nests on rooftops in towns and villages?

Answer: The nest-switching behavior may be an artifact of the novel nesting habitat created by humans and only recently available to the birds.

16. Explain why adult lesser kestrels are so willing to adopt the offspring of other kestrels.

Answer: In the past, the risk of misdirected parental care was so low that selection has not favored adults with the capacity to discriminate against young birds that are not their own offspring.

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 12: Principles of Social Evolution

Multiple Choice 1. Starlings sometimes assemble in large flocks that, in the evening, rise up in whirling flight together for 15 or 20 minutes in what looks like some kind of display. V. C. Wynne-Edwards suggested that this behavior is indeed a display that enables individual birds to assess just how many fellow starlings are living in the area so that they can adjust their breeding effort in the upcoming breeding season. In this way, they can avoid producing too many chicks and thereby avoid overpopulating their home range. This a group selectionist hypothesis because a. the idea is that starlings could evaluate the size of their local population or group. b. the flight behavior of the flock is something that cannot be explained in terms of any benefits to individuals and, thus, must be beneficial for the group. c. starlings do breed in such a manner as to avoid overpopulation. d. the suggestion is that the birds engage in costly behaviors in order to make decisions that are advantageous for other unrelated starlings.

Answer: d 2. Professor Reynolds claims that when male emperor penguins stand in the Antarctic winter, each with an egg cradled between his feet and his belly, the males’ parental behavior is “altruistic.” Reynolds is _______ because _______. a. correct; the males run some risk of dying during the long incubation period and so incur a fitness cost by being parental b. correct; the behavior, although risky, provides the help that is necessary to preserve the species over time c. incorrect; each male is incubating his own egg, not someone else’s d. incorrect; even though the behavior is costly, males have no option except to behave in this manner because of their high parental hormone levels Answer: c 3. In the bees, ants, and wasps (Hymenoptera), female workers are very closely related to their reproducing sisters only if their mother has mated with just one male because a. they will share exactly the same genetic information that makes up the paternal contribution to their genome. b. all of the daughters of a queen receive one-half their genome from their mother, whose eggs are genetically three-fourths alike. c. all females with the same mother are the product of a union between a haploid egg and a diploid sperm.

d. three-fourths of the genomes of sisters come from their mother, and one-fourth come from their father.

Answer: a Questions 4−7.

In a group of meerkats, a male gives a number of alarm calls that in total save the lives of two sisters as well as three offspring of another sibling. But by giving these alarm calls, the male is exposed to risk of attack from predators and eventually is killed by a hawk. As a result of a shortened life, he does not produce three surviving offspring that he otherwise would have had.

4. What was the cost to the male in units of inclusive fitness for his alarm-calling altruism? a. 0 b. 1.5 c. 1.75 d. 2.5 Answer: b 5. What was the benefit to the male in units of inclusive fitness for his alarm-calling altruism? a. 0 b. 1.5 c. 1.75 d. 2.5 Answer: c 6. What was the benefit to the male from his altruism in terms of indirect fitness? a. 0 b. 1.5 c. 1.75 d. 2.5 Answer: c 7. Which of the following traits is least likely to be considered a Darwinian puzzle? a. Monogamy in male songbirds b. Altruism in worker ants c. Camouflaged color patterns in grasshoppers d. Blood donation by college students Answer: c 8. If someone were to say the reason a bee population contains genetic variation is to enable natural selection to select the best hereditary variants, G. C. Williams would say that this claim is a. true, because without hereditary differences, natural selection is blocked. b. false, because selection can cause change even in genetically uniform populations. c. false, because some populations are known to exist without genetic variation. d. false, because it implies that genetic variation will be maintained in populations for future benefit even if the variant alleles reduce the fitness of individuals at present.

Answer: d

9. The rarer of two hereditarily different phenotypes can be considered an adaptation when the a. rare phenotype protects the more common phenotype, preventing predators from eating these individuals. b. rare phenotype becomes more common from one generation to the next because of its positive effect on individual fitness. c. mutant allele underlying the rare phenotype confers some reproductive success on those with this form of the gene. d. rare phenotype possesses the ability to adjust to changing conditions.

Answer: b Questions 10–13.

Bob gives up a chance to marry and have a family in order to go to work in a distant country.

Had he married, he would have had two surviving offspring. He sends money back to his sister, who as a result produces five surviving offspring instead of the two she would have had without Bob’s assistance.

10. What was Bob’s cost to himself in units of direct fitness (e.g., children)? a. 1 b. 1.5 c. 2 d. 3 Answer: a 11. What was Bob’s cost to himself in units of inclusive fitness (e.g., children)? a. 1 b. 1.5 c. 2 d. 3 Answer: a 12. What was Bob’s benefit to himself in units of inclusive fitness (e.g., children)? a. 0.5 b. 0.75 c. 1.5 d. 3 Answer: b 13. Bob’s decision was a. adaptive. b. maladaptive. c. adaptable. d. adaptationist.

Answer: b

14. In the digger bee, Centris pallida, some males engage in female defense polygyny, while smaller males exhibit scramble competition polygyny, which provides reduced fitness for these smaller males. What maintains the variation in the mating systems of males of this species? a. The differences in male behavior are fixed developmentally and thus not directly subject to selection. b. The focus of selection is on females, whose provisioning decisions produce males of different sizes; though small males gain fewer mates, some is better than none for the mothers. c. Variation among the males ensures that the greatest number of females are mated, which boosts the reproductive potential of this species. d. The mating system that provides lower fitness for individuals is becoming less common but has not yet disappeared because of the inefficiency with which selection acts on behavioral variations.

Answer: b

Short Answer 15. Explain why the coefficient of relatedness is important for biologists studying the evolution of altruism.

Answer: Measures of inclusive fitness are based in part on the degree to which two individuals are related, and the genetic consequences of helping for an individual depend on the helped individual’s coefficient of relatedness with the helper. Without the coefficient of relatedness, we couldn’t accurately calculate the costs and benefits of altruism.

16. The activity of N2RB gene declines in older mice and causes a decline in learning ability.

Some have suggested that this is beneficial, because it means older mice cannot forage as efficiently as they once did, which frees up resources for the next generation. How is this hypothesis based on group selection?

Answer: The trait of interest is said to cause individuals to sacrifice some reproductive opportunities in order to help another generation of mice to grow and reproduce.

17. Some researchers have claimed that group selection theory is required if we are to explain why people have the capacity to behave generously, nicely, and morally to other members of their group, whereas the selfish side of human behavior has been caused by natural selection.

Why is this claim inaccurate?

Answer: The researchers confuse the everyday meaning of selfish with the evolutionary meaning; if generous behavior is adaptive, then it is also selfish, in evolutionary terms.

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 13: Social Behavior and Sociality Multiple Choice 1. Refer to the figure below.

The point of the prisoner’s dilemma diagram is to a. illustrate the adaptive value of cooperation between two individuals. b. show that under most circumstances reciprocity would probably be selected against. c. predict that altruism rather than reciprocity explains why animals cooperate. d. show why reciprocity is so common and widespread in the animal kingdom.

Answer: b 2. What is wrong with the following statement: “An adaptation is a trait whose fitness benefits (B) exceed its costs (C).” a. An adaptation can have higher C than B if the trait helps the species survive. b. The benefits associated with an adaptation must be greater than the costs, and in addition the trait must help individuals to survive. c. The benefits associated with an adaptation must be greater than the costs, and in addition the difference between B and C must be greater than that associated with any other alternative trait. d. The benefits associated with an adaptation must be greater than the costs, and in addition the trait must be more common than any other alternative trait in the population.

Answer: c

3. Kin selection theory is most useful in helping explain a. cooperative hunting by the members of a lion pride. b. reciprocity that occurs by hunting in groups of lions. c. altruism exhibited by some hunting lions in a group. d. the exploitation of some helpful lions by others in their pride.

Answer: c 4. The prisoner’s dilemma describes a. the decision faced by aphids taken captive by slave-making ants over whether to escape or to cooperate with the ants. b. a model of decisions regarding defection or cooperation with another individual. c. reproductive decisions faced by animals at the edge of their species’ range regarding whether to hybridize with another species or continue searching for a member of their own. d. “buyer’s remorse” by a member of a mated pair, wishing to choose a different mate but facing the high costs of searching.

Answer: b 5. Honeyguides (a small African bird) lead humans to bees’ nests so the humans will make the wax honeycomb available to them. Similarly, cleaner fish remove ectoparasites from other reef fish. These are examples of a. the prisoner’s dilemma. b. kin selection. c. reciprocity. d. altruism.

Answer: c 6. Vampire bats need to eat often, and their only food is blood. When one bat is unsuccessful at gaining a meal, it returns to a communal roost where another bat is likely to give it a small amount of food. Work by Carter and Wilkinson (2015) suggests that this arrangement meets the conditions needed for a. the prisoner’s dilemma. b. kin selection. c. reciprocity. d. altruism.

Answer: c 7. Expression of behavioral syndromes is sometimes referred to as a. defection. b. an ecological constraint. c. social behavior. d. animal personality.

Answer: d

8. In reciprocity, we hypothesize that an individual engages in a selfless act because they will be “repaid” by the recipient in the future. This expectation is likely to occur in all of the following scenarios, except: a. when individuals are long-lived and the likelihood of meeting again is high. b. when an individual has observed a potential recipient helping others. c. when the individuals are different species and can distinguish their payoff from the arrangement. d. when the recipient can cheat and avoid repaying the altruistic act.

Answer: d

Short Answer Questions 9–12.

Apply each type of hypothesis to address the question: Why do lions hunt together?

9. Cooperation or mutualism hypothesis Answer: Each member of the team gains more meat per individual per day as a result of combining forces to capture prey.

10. Reciprocity hypothesis Answer: Though some individuals may suffer injury by helping their companions capture of dangerous prey, they are later rewarded when others help them capture prey in return.

11. Altruism hypothesis Answer: Some individuals take risks that reduce their fitness, such as tackling dangerous prey to help their companions, with the consequence that the fitness of these other individuals is raised.

12. Selfish exploitation hypothesis Answer: Some lions simply follow others that do the actual risk-taking and expending of energy when capturing prey; these individuals, in effect, parasitize the efforts of their companions.

13. There are many costs and benefits to cooperative breeding. Select two of the proposed hypotheses and explain how they apply to cooperative breeding: kin selection hypothesis, group augmentation hypothesis, ecological constraints hypothesis, life history hypothesis, benefits-ofphilopatry hypothesis, temporal variability hypothesis, and bet-hedging hypothesis.

Answer: (The provided list of hypotheses can be omitted or shortened to match instructor’s needs and coverage in the course). See page 494 in the text for a brief description of each hypothesis.

This question could also be adapted by asking students to “Explicitly highlight an example from class that supports your answer.”

14. Refer to the figure below.

The female white-fronted bee-eater has several options to choose among when deciding to reproduce. What factors affect whether the female stays in her natal territory?

Answer: If one or both of her parents have disappeared from the natal site, she is unlikely to remain as a helper because her relatedness to the offspring is low. If she is courted by a dominant male with an established territory and helpers, she will leave the natal site to breed. If only subordinate males are available, she will be a non-participant or remain at the natal site as a helper (to her parents).

15. Refer to the figure below.

Based on the data in the figure, describe why female Polistes wasps are more likely to be helpers to a foundress rather than establish their own nest as a solitary foundress.

Answer: Solitary foundresses have similarly low reproductive output compared to helper foundresses that only succeed in subordinate egg laying opportunities, but they have much lower reproductive success compared to helpers that inherit an established colony. These females have 2−4 times more offspring than the solitary foundress.

Test Bank to accompany

Animal Behavior, Eleventh Edition John Alcock, Linda Green, Paul Nolan, and Dustin Rubenstein Chapter 14: Human Behavior

Multiple Choice 1. Which hypothesis is based on group-selection theory? a. Adoption provides assistance for offspring of relatives, thereby enjoying an indirect fitness benefit. b. An adopter gains by demonstrating wealth, which makes the head of the family more attractive to potential partners in polygynous societies. c. An adopter acquires offspring who will help produce material wealth for his or her family. d. An adopter benefits his or her society by providing assistance to an individual otherwise likely to die or be a burden to the tribe or clan.

Answer: d 2. Which hypothesis is based on kin-selection theory? a. Adoption provides assistance for offspring of relatives, thereby enjoying an indirect fitness benefit. b. An adopter gains by demonstrating wealth, which makes the head of the family more attractive to potential partners in polygynous societies. c. An adopter acquires offspring who will help produce material wealth for his or her family. d. An adopter benefits his or her society by providing assistance to an individual otherwise likely to die or be a burden to the tribe or clan.

Answer: a 3. Which hypothesis is based on natural-selection theory? a. Adoption provides assistance for offspring of relatives, thereby enjoying an indirect fitness benefit. b. An adopter gains by demonstrating wealth, which makes the head of the family more attractive to potential partners in polygynous societies. c. An adopter acquires offspring who will help produce material wealth for his or her family. d. An adopter benefits his or her society by providing assistance to an individual otherwise likely to die or be a burden to the tribe or clan.

Answer: c 4. Which hypothesis is based on sexual-selection theory?

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a. Adoption provides assistance for offspring of relatives, thereby enjoying an indirect fitness benefit. b. An adopter gains by demonstrating wealth, which makes the head of the family more attractive to potential partners in polygynous societies. c. An adopter acquires offspring who will help produce material wealth for his or her family. d. An adopter benefits his or her society by providing assistance to an individual otherwise likely to die or be a burden to the tribe or clan.

Answer: b 5. What significance can we attach to the fact that the verbal ability scores of adopted children are more similar to those of their biological parents than to their those of their adoptive parents? a. This shows the importance of early experience in shaping a child’s behavior. b. This demonstrates that environment is more important than genetics in the development of a person’s verbal abilities. c. This constitutes a scientific conclusion that the correlation between verbal ability scores of biological parents and the children that have been reared by others is about 0.35. d. This is contrary to the idea that people experiencing different environments should exhibit different behaviors.

Answer: d

Short Answer 6. When choosing between two males of the same age but different heights, a young, unmarried woman selects the taller individual. What are some of the possible adaptive values of her choice?

Answer: (Answers will vary.) Tall men have genes that make them more protective of their mates than short men are. Tall men may be healthier and more physically fit and would produce stronger, healthier offspring. Tall men may be more confident and therefore more successful in their careers, making them better providers.

7. What makes the study of human twins valuable for understanding the genetic causes of behavior?

Answer: Comparing certain characteristics of twins enables us to test the hypothesis that some differences among individuals are genetically determined.

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