Animal Behavior (4030) Exam 1

Which of the following statements are clearly Darwinian puzzles?

a. Salmon can smell a few molecules of chemicals in the stream in which they were born.

b. Adult birds scream when caught by a predator because of the pain.

c. If you add two or three eggs to the nests of some birds, the parent birds rear them successfully along with the young from eggs they laid.

d. Female lions often nurse offspring that are not their own.

e. c and d.

E. C & D

If a trait is the product of natural selection, the trait will

a. provide a net reproductive gain to the species as a whole.

b. raise the reproductive success of individuals bearing it more than other alternative forms of the trait in the population.

c. enhance the survival of the fittest individuals.

d. help preserve the species against the risk of extinction.

e. maximize the survival chances of close family members within the species.

B. raise the reproductive success of individuals bearing it more than other alternative forms of the trait in the population.

T/F Ultimate hypotheses about behavior address mechanisms within an organism that cause it to behave in a particular way

FALSE

T/F Ultimate hypotheses about behavior address the genetic and developmental causes of behavior

FALSE

T/F Ultimate hypotheses about behavior address the fitness advantages of behavior

TRUE

T/F Ultimate hypotheses about behavior cannot be tested by the method of "strong inference"; only proximate hypotheses can

FALSE

T/F Ultimate hypotheses about behavior address how the behavior has changed over evolutionary time.

TRUE

T/F Ultimate hypotheses about behavior address the evolutionary history of the behavior

TRUE

A-E. When a tropical moth of the genus Automeris is touched on the thorax it lifts its forewings up abruptly, exposing its brightly colored hindwings. What causes the moth to behave this way? For each possible explanation (hypothesis), is it focusing on ultimate or proximate causes of behavior?

A. The behavior is instinctive.

B. Wing flipping scares some predators away

C. The behavior is the product of a special set of muscle contractions

D. The behavior is an evolutionarily modified version of wing movements that ancestral moths used for a different purpose

E. Automeris moth genes influence the way the adult animal's nervous system forms connections between its muscles and its wings

A. PROXIMATE

B. ULTIMATE

C. PROXIMATE

D. ULTIMATE

E. PROXIMATE

Scientific investigations about animal behavior begin with a question about what causes an animal to do something. We then devise a working ________ , a possible answer to the question

a. prediction

b. hypothesis

c. result

d. group selectionist interpretation

e. conclusion

B. Hypothesis

Observation: Killdeer react differently to two different threats to their nests, one posed by predators and the other posed by cows.

You wonder: How are killdeer able to differentiate these different threats and respond accordingly?

Statement: The killdeer's creative responses are the result of its ability to use conscious thought to solve its problems in nest defense.

This Statement best represents

a. a hypothesis.

b. a causal question.

c. a statistical result.

d. an ultimate hypothesis.

A. A Hypothesis

The seeds retrieved in springtime are used mainly to feed young at the nest

Proximate or Ultimate and type of explanation :

(a) a genetic-developmental explanation.

(b) a physiological-psychological explanation.

(c) an evolved function explanation.

(d) an evolutionary history explanation.

Ultimate ; C an evolved function explanation

Clarke's nutcracker evolved from an ancestral jay that possessed the capacity for spatial memory

Proximate or Ultimate and type of explanation :

(a) a genetic-developmental explanation.

(b) a physiological-psychological explanation.

(c) an evolved function explanation.

(d) an evolutionary history explanation.

Ultimate ; D an evolutionary history explanation

Birds retrieve hidden food efficiently items because they have a large hippocampus

Proximate or Ultimate and type of explanation :

(a) a genetic-developmental explanation.

(b) a physiological-psychological explanation.

(c) an evolved function explanation.

(d) an evolutionary history explanation.

Proximate ; B a physiological-psychological explanation

The ability to retrieve food is genetically controlled, not environmentally determined

Proximate or Ultimate and type of explanation :

(a) a genetic-developmental explanation.

(b) a physiological-psychological explanation.

(c) an evolved function explanation.

(d) an evolutionary history explanation.

Proximate ; A a genetic-developmental explanation

Hiding and retrieving seeds are innate, or instinctive, behaviors

Proximate or Ultimate and type of explanation :

(a) a genetic-developmental explanation.

(b) a physiological-psychological explanation.

(c) an evolved function explanation.

(d) an evolutionary history explanation.

Proximate ; A a genetic-developmental explanation

Birds learn to hide seeds from their mothers, not their fathers

Proximate or Ultimate and type of explanation :

(a) a genetic-developmental explanation.

(b) a physiological-psychological explanation.

(c) an evolved function explanation.

(d) an evolutionary history explanation.

Proximate ; A a genetic-developmental explanation or B a physiological-psychological explanation

Birds retrieve hidden food efficiently to survive even the harshest of winters

Proximate or Ultimate and type of explanation :

(a) a genetic-developmental explanation.

(b) a physiological-psychological explanation.

(c) an evolved function explanation.

(d) an evolutionary history explanation.

Ultimate ; C an evolved function explanation

It enables birds with the best retrieval ability to safeguard the breeding stock of the species

Proximate or Ultimate and type of explanation :

(a) a genetic-developmental explanation.

(b) a physiological-psychological explanation.

(c) an evolved function explanation.

(d) an evolutionary history explanation.

Ultimate ; C an evolved function explanation

** BASED ON GROUP SELECTION **

Birds are primed hormonally during a particular stage of their life, which promotes their ability to remember and locate seeds later in life.

Proximate or Ultimate and type of explanation :

(a) a genetic-developmental explanation.

(b) a physiological-psychological explanation.

(c) an evolved function explanation.

(d) an evolutionary history explanation.

Proximate ; B a physiological-psychological explanation

By catching and retrieving food far and wide, birds communicate territorial ownership of their breeding site to rival birds, thus increasing their chances of nest success

Proximate or Ultimate and type of explanation :

(a) a genetic-developmental explanation.

(b) a physiological-psychological explanation.

(c) an evolved function explanation.

(d) an evolutionary history explanation.

Ultimate ; C an evolved function explanation

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.

Which of the following statements about those conditions is incorrect?

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

b. Any changes that took place in the past must have promoted greater population stability in this bird.

c. Better than average song "rememberers" must have been able to transmit their superior abilities to their offspring.

d. Better than average song "rememberers" must have had higher fitness on average than sparrows with lesser memory skills.

B. Any changes that took place in the past must have promoted greater population stability in this bird.

When an evolutionary biologist 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 small and should be ignored.

d. the behavior is unlikely to respond to selection, since there is no variation in the species.

B. individuals with different forms of that gene exhibit different behaviors.

The presence of a predator triggers the development of an antipredator phenotype, as seen in some aphids. We call such ability to change

a. a polyphenism.

b. a predator-induced polyphenism.

c. phenotypic plasticity.

d. developmental homeostasis.

e. a polymorphism.

C. phenotypic plasticity.

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 genetic differences are necessary for the development of all phenotypic variations.

b. No, because this is equivalent to saying that the two traits are environmentally determined, which is incorrect.

c. Yes, because as polyphenisms 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 massively important for the development of all phenotypes, especially behavioral ones.

C. Yes, because as polyphenisms illustrate, some differences in gene-environment interactions are caused only by differences in the environment side of the interaction

A main reason for making the proximate-ultimate distinction in animal behavior research is to

a. shine light on the importance of group-level selection in causing the evolution of behavioral adaptations.

b. emphasize that ultimate research is superior to proximate research.

c. eliminate unproductive arguments that arise from confusing these two logically distinct and complementary levels of analysis.

d. make all university professors integrate these levels of analysis in their research.

C. eliminate unproductive arguments that arise from confusing these two logically distinct and complementary levels of analysis.

Tiger salamanders occur in two forms: cannibal and noncannibal. Researchers have wondered why these salamanders switch from one form to another. Some have suggested that switching to the cannibal form gives that individual an abundant food supply not available to its noncannibal neighbors. This suggestion constitutes an example of a(n)

a. causal question.

b. conclusion.

c. anecdote.

d. hypothesis.

e. prediction.

D. hypothesis

Tiger salamanders occur in two forms: cannibal and noncannibal. Researchers have wondered why these salamanders switch from one form to another. Some have suggested that switching to the cannibal form gives that individual an abundant food supply not available to its noncannibal neighbors. This suggestion is an example of a(n)

a. developmental explanation.

b. physiological explanation.

c. adaptive value explanation.

d. explanation relating to evolutionary history.

C. adaptive value explanation.

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. (GROUP SELECTION)

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 more effectively than they would otherwise.

d. older star-nosed moles leave more copies of their genes to the next generation than others.

C. individuals that ignore some categories of potential sensory inputs forage more effectively than they would otherwise.

Male wasp pounces on orchid flower petal

a. Releaser

b. Innate releasing mechanism

c. Fixed action pattern

Fixed action pattern

Odors coming from orchid flower petal

a. Releaser

b. Innate releasing mechanism

c. Fixed action pattern

Releaser

Element of the wasp's neural network used for detecting odor

a. Releaser

b. Innate releasing mechanism

c. Fixed action pattern

Innate releasing mechanism

Causal Question ...

a. A question about why or how something happens

b. The rejection of a possible explanation

c. A possible explanation

d. Results

e. What ought to be observed if a given hypothesis is true

A. a question about why or how something happens

Hypothesis ...

a. A question about why or how something happens

b. The rejection of a possible explanation

c. A possible explanation

d. Results

e. What ought to be observed if a given hypothesis is true

C. a possible explanation

Prediction ...

a. A question about why or how something happens

b. The rejection of a possible explanation

c. A possible explanation

d. Results

e. What ought to be observed if a given hypothesis is true

E. What ought to be observed if a given hypothesis is true

Data to test a prediction ...

a. A question about why or how something happens

b. The rejection of a possible explanation

c. A possible explanation

d. Results

e. What ought to be observed if a given hypothesis is true

D. Results

Conclusion ...

a. A question about why or how something happens

b. The rejection of a possible explanation

c. A possible explanation

d. Results

e. What ought to be observed if a given hypothesis is true

B. The rejection of a possible explanation

Evolutionary game theory is a tool used by behavioral biologists to

a. understand the adaptive basis of animal play.

b. understand the choices animals make as they compete with one another for resources.

c. calculate mean survival payoffs for individuals occupying different ecological niches.

d. estimate the energy payoffs of given foraging strategies.

B. Understand the choices animals make as they compete with one another for resources

Contest resolution that is mediated by harmless, non-contact threat displays is a Darwinian puzzle because

a. the winners of these interactions have expended time and energy asserting control of resources they will use to raise their fitness.

b. the losers of these interactions concede defeat without actual fighting, thereby giving up resources that would otherwise raise their fitness.

c. the winners of these interactions would benefit killing those competitors that will again return to challenge them for key resources.

d. the loser's refusal to fight strips the species of the means by which it could cull excess individuals from the species as a whole.

B. the losers of these interactions concede defeat without actual fighting, thereby giving up resources that would otherwise raise their fitness.

Game Theory or Optimality Theory?

A redshank forages solitarily on a mudflat, exploiting patches of food as it goes.

Optimality Theory

Game Theory or Optimality Theory?

The long-term persistence of two competing types of fly larvae, rovers and sitters, in the same population

Game Theory

Game Theory or Optimality Theory?

Smaller, subordinate turnstones search for food at inferior feeding sites instead of feasting on juicy invertebrates within the seaweed litter controlled by competitive, dominant birds

Game Theory

Game Theory or Optimality Theory?

A northwestern crow out hunting for food, grabs a whelk, flies up with it to about 5 m above the ground, and drops it

Optimality Theory

An adaptation is a trait that

a. confers fitness.

b. confers very high fitness.

c. confers higher net fitness to individuals that possess it compared to other individuals in the population with an alternative form of the trait.

d. confers a fitness advantage that is approximately equal to its fitness costs.

e. none of the above

C. confers higher net fitness to individuals that possess it compared to other individuals in the population with an alternative form of the trait.

Game Theory or Optimality Theory?

A marine iguana initially forages primarily in the intertidal zone but switches to foraging in the subtidal zone as the temperature cools

Optimality Theory

Bluegill sunfishes exhibit flexible reproductive behavior, as small, subordinate males who are typically nonterritorial can adopt territorial behavior when the opportunity presents itself. Following game theoretic language, the different behavioral types are each best labeled ______________ .

a. a tactic.

b. an alternative strategy.

c. a learned strategy.

d. an optimal strategy.

e. a high fitness tactic.

A. A tactic

Proximate or Ultimate?

Males are stimulated by the sounds made by nearby males

Proximate

Proximate or Ultimate?

The species acquired the capacity from a sparrow-like ancestor

Ultimate

Proximate or Ultimate?

Birds possess an especially high density of testosterone-binding receptors in their plumes and brains

Proximate

Proximate or Ultimate?

Male sparrows are striving to attract mates

Ultimate

Proximate or Ultimate?

The full development of these traits allows males to control superior feeding territories

Ultimate

The ability to hear ultrasound in noctuid moths is considered an anti-predator adaptation because it apparently enables individuals to hear and avoid nocturnal, ultrasound-using bats. Imagine that you wished to test this hypothesis via the comparative method.

For each of the following cases indicate whether it most likely involves convergent evolution, divergent evolution, or neither.

a. All other species of noctuid moths also have ears on their thorax that respond to ultrasound

b. All the species in one evolutionary lineage that includes the noctuid moths and many other moths belonging to several superfamilies also have ears that respond to ultrasound

c. Some diurnal noctuid moths have ears, but are largely or totally incapable of hearing ultrasound

d. Six species of noctuid moths found only on the Pacific Ocean islands of Tahiti and Moorea have ears, can detect ultrasound but do not react to this stimulus with an

a. Neither

b. Neither

c. Divergent Evolution

d. Divergent Evolution

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 gifts in white silk. What is the function of this behavior? Stålhandske suggested the males wrapped their gifts in order to make them look like the white, silk-covered egg sacs that mated females make and hold in their jaws to protect them until the spiderlings hatch.

The last sentence in the paragraph above best represents:

a. a causal question

b. a hypothesis

c. a prediction

d. test evidence e. conclusion

B. a hypothesis

What theory was Stålhandske using to explore this species' courtship behavior?

a. conditional strategy theory

b. game theory

c. optimality theory

d. sensory exploitation theory

D. sensory exploitation theory

Which of the following two predictions might Stålhandske have felt was likely to be correct, given her educated guess that males might be making their nuptial gifts to look like eggs sacs?

a. A female should be more eager to accept a nuptial gift covered in silk that has been experimentally colored brown instead of white. (Yes/No)

b. Natural silk-covered prey should be comparable in light reflectance to silken egg sacs. (Yes/No)

A. No

B. Yes

The evolution of "true communication" requires

a. signal perception by the receiver and signal production by the sender.

b. fitness benefits for both the sender and the receiver.

c. the relay of information via cues.

d. selection pressure only on the sender of a signal.

e. both a. and b.

E. both a and b

A trait is ________ when we are able to provide evidence that it evolved to modify receiver behavior.

a. a signal

b. a cue

c. an index

d. a handicap

e. a mimetic trait

A. a signal

In the funnel-web spider, males fight over web sites. Further, males differ in weight only because of differences in their nutritional histories. Susan Riechert found that spiders are able to assess the weight of opponents, and that the smaller spider of two contestants retreated rather than stayed to fight. Weight in this case should best be viewed as _______ of fighting ability.

a. a signal

b. a cue

c. an honest signal

d. a costly signal

B. a cue

White-tailed deer raise their tails when they spot a predator approaching; the predator upon seeing this typically gives up its pursuit once it knows that the faster prey species has seen it. This is an example of

a. stotting.

b. eavesdropping.

c. honest signaling.

d. deceitful signaling.

C. Honest Signaling

Deceptive signaling is widespread in nature with, 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 a result of successful pollination is actually pretty small.

b. natural selection should 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 species to grow, since the deceptive plants slow the ability of male wasps to fertilize all the eggs of their females.

d. it is impossible to figure out how orchid flowers evolved to smell like the females of certain wasps.

B. natural selection should favor discriminating behavior on the part of male wasps so that they do not waste time, energy, and even sperm on orchid flowers.

Sexual selection

a. explains the evolution of ornaments and armaments in males, but not in females in species

with sex role reversal.

b. can only act on traits not under natural selection.

c. can lead to the evolution of elaborate traits if they help one sex gain an advantage in mating,

even if they also lead to higher predation risk.

d. is similar to natural selection in that it acts on traits that increase the species' prospects of

persistence

c. can lead to the evolution of elaborate traits if they help one sex gain an advantage in mating,

In a species with sex role reversal, males contribute more parental investment

than females. In this species, you could also predict that

a. there will be more sexually active males than females.

b. there will be equal reproductive variance in males and females.

c. females are more likely to be competitive and have ornaments to attract mates.

d. sexual selection will be weaker than natural selection

c. females are more likely to be competitive and have ornaments to attract mates.

When there are many more sexually active females in the population than

males, we have

a. a female-biased operational sex ratio (OSR).

b. evidence of greater mortality in females than males.

c. an example of sex-role reversal.

d. direct evidence for greater parental investment (PI) by males.

e. an instance of sexual dimorphism

a. a female-biased operational sex ratio (OSR).

A male transfers chemicals from his ejaculates to a female during mating.

For each of the following statements, indicate whether it represents a hypothesis based

on natural selection (a), sexual selection (b), or neither (c). These male-derived chemicals

4. kill sperm already in storage within the female deposited by a previous male.

5. render the female unreceptive to future sexual advances by rival males.

6. have anti-parasitic properties that promote the survival of his mate.

7. serve to nourish the embryos fertilized by the male.

8. act to promote the fertility of the female to maximize the growth rate of the population.

4. b, natural selection promotes competitive fertilization success

5. b, natural selection promotes competitive fertilization success

6. a, sexual selection promotes survival

7. a, sexual selection promotes survival

8. c. neither, group selection

In the narwhal (a species of whale), females live in groups and the

males have an elongated tooth, called a tusk. You hypothesize that the tusk is a

functional weapon that has evolved by sexual selection that enables some males to

monopolize harems of females. You wish to test this hypothesis using the comparative

method. Which of the following predictions would represent legitimate cases of

convergent evolution. Put ‘a’ for legitimate or ‘b’ for illegitimate.

9. Male beluga, the narwhal’s closest relative, will also use their teeth in clashes over access to

females.

10. The bodies of male narwhals should be marked by scars of the sort that could be produced

by narwhal tusks.

11. In the warthog, a wild pig, in which females live in bands, the males should have much

larger protruding tusks than the females.

12. In the dik-dik, an African antelope in which females are monogamous and solitary, males

and females should have small tusks of equivalent size.

13. In the giant scarab beetle, males have evolved large horns used in fights over groups of

females.

9. b, illegitimate

10. b, illegitimate

11. a, legitimate

12. b, illegitimate

13. a, legitimate

or each of the following phenomena, circle ‘a’ if it is an example of

parental investment (PI). Circle ‘b’ if it constitutes mating effort (ME).

14. A male katydid has given his mate an edible spermatophore containing orange carotenoid

pigments that are incorporated into her eggs to protect them.

15. A female dance fly inflates her abdomen and holds her dark, hairy legs around her body,

making herself appear as attractive as possible to potential mates.

16. A male African Jacana constructs a nest into which the eggs of a number of different

females are deposited.

17. A male spider amputates his own sperm-transferring pedipalps during copulation so as to

block the female’s genital opening.

14. a, parental investment

15. b, mating effort

16. a/b, both pi and me

17. b, mating effort

Why might male Mormon crickets have a lower potential reproductive rate (PRR)

than females?

a. Because they make relatively small gametes compared to the eggs 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

c. Because males donate a very large, hard to replace spermatophore to each mate.

Although some male crab spiders find and mate with adult female spiders, others

that find immature females remain with them although the subadult females are incapable

of mating until they become adults. This behavior would puzzle most evolutionary

biologists because

a. The genetic basis for this behavior would be very difficult to determine.

b. Mating is instinctive in spiders and therefore all males should behave the same, either mating

with adult females only or guarding subadult females only.

c. Males that guard subadults cannot use the time to find receptive females.

d. One would think that immature female spiders should accept and store sperm from males in

order to permit good female-finding males to have time to find many mates.

c. Males that guard subadults cannot use the time to find receptive females.

Male fifteen-spined sticklebacks that shake their body frequently when

courting also provide more nest fanning of their eggs, and are preferred by choosy

females. This is an example of

a. direct benefits.

b. the good genes model of sexual selection.

c. the sexy-son model of sexual selection.

d. sexual conflict

a. direct benefits.

Female widowbirds that prefer to mate with long-tailed males produce long-

tailed sons and daughters that also prefer males with long tails. This is an example of

a. direct benefits.

b. the good genes model of sexual selection.

c. the sexy-son model of sexual selection.

d. sexual conflict

c. the sexy-son model of sexual selection.

Large male fruit flies have a mating advantage as a result of their superior

competitive ability. Females mating with larger males experience reduced longevity

because of toxic elements in the male ejaculate. This is an example of

a. direct benefits.

b. the good genes model of sexual selection.

c. the sexy-son model of sexual selection.

d. sexual conflict.

d. sexual conflict.

Mating in scorpionflies is based on males acquiring dead insects to present to

choosy females as “nuptial gifts”, which allow longer copulation time, increased

fertilization success and increased nutritional benefits for egg provisioning. This is an

example of:

a. inter-sexual selection based on aesthetic mate preference.

b. inter-sexual selection based on direct fitness benefits.

c. inter-sexual selection based on indirect fitness benefits.

d. intra-sexual selection based on male competition

b. inter-sexual selection based on direct fitness benefits.

Benjamin Oldford and Jennifer Fewell asked the question: why are some members

of the bee genus Aphis highly polyandrous. They stated that polyandry may enhance

the disease resistance of the queen's offspring.

This statement constitutes a

a. conclusion.

b. prediction.

c. hypothesis.

d. test evidence.

e. causal question.

c. hypothesis.

Benjamin Oldford and Jennifer Fewell asked the question: why are some members

of the bee genus Aphis highly polyandrous. They stated that polyandry may enhance

the disease resistance of the queen's offspring.

The theoretical basis of this statement is

a. group selectionist thinking.

b. the idea that females might derive material benefits from mate choice.

c. the idea that females might derive indirect benefits from promiscuity.

d. direct benefits theory.

e. inclusive fitness theory

c. the idea that females might derive indirect benefits from promiscuity.

Polygyny make take several forms. Which of the following is (are) examples?

a. Bighorn rams fight with other males to monopolize females.

b. A female fairy wren engages in a copulation with a male other than her social mate.

c. Males of the Australian antechinus mouse try to outrace rivals to receptive females.

d. all of the above.

e. a and c.

e. a and c.

Ghalambor and Martin (2001) found that a North American species of thrush

placed higher value on their current nest full of offspring than did a similar South

American species. This differential response is likely 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 South America

b. South American birds generally living longer than those in North America.

For each of the following statements pertaining to the question: Why does

siblicide occur?

Circle “a” if it is an ultimate hypothesis, “b” if it is a proximate hypothesis, or “c” if it is not a

hypothesis at all. Note, consider wording carefully, as all critical scientists should.

2. The particularly small size of the youngest chick during times of famine acts as a releaser of

aggressive behavior in the eldest chick.

3. Inclusive fitness of the elder chick is maximized if it kills its younger sibling when resources are

scarce.

4. Elder chicks sometimes acquire siblicidal tendencies by mimicking their parents' aggressive

behavior directed against nest intruders.

5. Siblicide should also occur in species, outside of birds, that have a variable food supply.

6. The senior chick attacks its sibling because first-laid eggs receive large quantities of androgens—

hormonal facilitators of aggression.

2. b, proximate

3. a, ultimate

4. b, proximate

5. c, neither

6. b, proximate

Question: In the black eagle, why does obligate siblicide of the marginal chick occur?

Hypothesis: Marginal chicks serve as insurance to parents against the early loss or infirmity of

the senior chick.

For each of the following, circle “a” if it is a prediction that correctly employs the comparative

method, or “b” if it does not. Circle “c” if the statement is not a prediction at all. Again, please

pay attention to the wording.

7. Removing the “insurance” egg from the nests of another eagle species that also practices obligate

siblicide should reduce the mean number of fledglings per nest.

8. In the masked booby, a species distantly related to the black eagle that practices obligate siblicide,

marginal chicks were found to be the sole fledglings from 13 nests.

9. In the masked booby, a species distantly related to the black eagle that practices obligate siblicide,

removing the “insurance” egg from nests should also reduce parental fitness.

10. In an egret species distantly related to the black eagle, the data indicate that obligate siblicide also

enhances the fitness prospects of the parents.

7. b, does not employ comparative method

8. c, neither

9. a, employs comparative method

10. a, employs comparative method

If the average paternity of a male caring for a brood of offspring is 80%, then for every

five offspring cared for, the male's parental investment will on average yield how many

descendants?

a. 1

b. 2

c. 3

d. 4

e. 5

d. 4

Females of many species mate with more than one male, producing broods of mixed

paternity. The existence of such mixed broods in a given species

a. reduces the long-term costs of male parental care.

b. reduces the benefits of male parental care.

c. increases the likelihood that male parental care will evolve.

d. does not affect the net fitness payoff of a given unit of male parental care.

e. none of the above.

b. reduces the benefits of male parental care.

Helping at the nest is observed in Seychelle’s warbers. Which of the following pieces of

evidence would NOT support your hypothesis that helping is a behavioral tactic under a

conditional strategy?

a. Small young birds are more likely to be helpers than large older birds.

b. Helping is more prevalent in habitats where nest sites are limited than where nest sites are

abundant.

c. Individuals that were helpers at one stage are breeders at later stages of their lives.

d. Helping and breeding are genetic alternatives.

e. High quality territories should have more helpers than low quality territories

d. Helping and breeding are genetic alternatives.

Circle “a” for true, “b” for false:

Indirect fitness benefits associated with acts of altruism increase as the degree of relatedness between

the altruist and the recipient of the helpful act increases.

a, true

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.

3. What was the direct fitness cost to the male, in genetic units, for his alarm-calling altruism?

a. 0

b. 0.25

c. 1.5

d. 1.75

c. 1.5

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.

What was the indirect fitness benefit to the male, in genetic units, for his alarm-calling

altruism?

a. 0

b. 0.25

c. 1.5

d. 1.75

d. 1.75

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.

What was the indirect fitness benefit to the male, in genetic units, for his alarm-calling

altruism?

a. 0

b. 0.25

c. 1.5

d. 1.75

d. 1.75

According to Hamilton’s rule, is this alarm-calling behavior adaptive?

a. Yes, because the direct fitness cost of the behavior was lower than the indirect fitness

benefit.

b. Yes, because any behavior that delivers indirectly benefits is expected to be adaptive.

c. No, because the direct fitness cost of the behavior was higher than the indirect fitness benefit.

d. No, because any behavior that results in zero direct fitness benefit cannot be adaptive

a. Yes, because the direct fitness cost of the behavior was lower than the indirect fitness

benefit.

why do lions hunt together?

Although some individuals lose temporarily by helping out their companions in the capture of

dangerous prey, they are repaid when those they helped pay them back at a time when the helper is

in special need of food.

Reciprocal altruism hypothesis

Why do lions hunt together?
Each member of the team gains more meat per individual per day as a result of combining forces to

capture prey

mutualism hypothesis

Why do lions hunt together?
Some lions join others in order to thwart their efforts at prey capture; these individuals expend time

and energy and run the risk of retribution as they alert prey to the approach of their companions.

spite hypothesis

Why do lions hunt together?
Some lions simply follow others that do the actual risk-taking and energy-expending when capturing

prey; these individuals in effect parasitize the efforts of their companions

selfish-exploitation hypothesis

Why do lions hunt together?
Some individuals take risks that reduce their fitness to help others, such as their siblings, bring

down dangerous prey, with the consequence that the fitness of these other individuals is raised

altruism hypothesis

According to one of Randy Thornhill's hypotheses, rape of strangers by men has

parallels to forced copulation in Panorpa scorpionflies. In scorpionflies, males unable to offer

nuptial gifts use the low-fitness gain, last chance tactic of trying to make females copulate with

them. According to this hypothesis, human males unable to attract willing sexual partners might

also use rape as a reproductive option of last resort. Under this hypothesis, rape constitutes

a. a hereditary strategy maintained in the population by frequency-dependent selection.

b. a tactic belonging to a conditional reproductive strategy.

c. violent antisocial behavior with no adaptive value.

d. a maladaptive byproduct of otherwise adaptive psychological attributes of men.

e. a trait that will increase steadily over time

b. a tactic belonging to a conditional reproductive strategy.

Why do women appear to have a preference for wealthy men, all other things begin

equal?

Perhaps this preference stems from the material benefits that women can secure from such

partners for themselves and their offspring

hypothesis

Why do women appear to have a preference for wealthy men, all other things begin

equal?

If so, women who abandon their mates for other men should tend to secure greater resources

from their new partners than their old partners would have been able to provide

prediction

Why do women appear to have a preference for wealthy men, all other things begin

equal?

Alternatively, perhaps wealthy men have been able to dominate their rivals, an ability that

stems from genetic factors inherited from their fathers.

hypothesis

The FOXP2 gene regulates the activity of other genes that contribute to the development of

particular parts of the brain essential for language

proximate

Hominid ancestors with better protolanguage had higher fitness than those with less speaking facility

ultimate

Our brains have circuits that integrate visual and auditory stimuli associated with speech, enhancing

our facility with language

proximate

Cells in part of our brain are responsive to the subtle movements of the lips, which contribute to our

ability to comprehend the complex vocalizations of fellow humans.

proximate

Speech is the focus of sexual selection, with female choice favoring males with exceptional language

skills.

ultimate