Deck 18: The Evolution of Sociality

Question 1

Which of the following equations illustrates the correct relationship?

A)Indirect fitness + Direct fitness = Inclusive fitness
B)Inclusive fitness + Direct fitness = Indirect fitness
C)Indirect fitness + Inclusive fitness = Direct fitness
D)Direct fitness - Inclusive fitness = Direct fitness

Answer 1

A

Question 2

An alarm call benefits multiple individuals,both related and unrelated (r = 0).Can this behavior still evolve according to Hamilton's rule? (There are 1,2,…,A individuals that are related to the donor by r₁,r₂,…,rA and receive benefits b₁,b₂,…,bA)

A)No, unrelated individuals will automatically set the benefits to 0, as Hamilton's rule for multiple individuals is .
B)No, this case no longer addresses inclusive fitness, and Hamilton's rule does not apply.
C)Yes, if there are more related individuals benefiting than unrelated individuals, as Hamilton's rule for multiple individuals is .
D)Yes, as long as the benefits to related individuals satisfy .

Answer 2

D

Question 3

Based on the model for conventional signals below,which signal level should an individual of medium ability adopt?

A)A
C)C
B)B
D)D

Answer 3

A

Question 4

Which of the following statements illustrates the free-rider problem?

A)By reliably reciprocating a cooperative behavior, all individuals in the population increase their fitness.
B)Some daughters forego having offspring of their own as they help their mother with brood care.
C)An individual spends only half an hour grooming others for each hour of grooming it has received.
D)Some individuals forgo reproduction to avoid overpopulation of a species' habitat.

Question 5

Among which of the following groups of organisms is cooperation via reciprocal altruism most likely to evolve (assuming all else is equal)?

A)Birds from across a species' range that congregate for a short time at a resting spot during migration
B)Short-lived, immobile tidal organisms that are in constant contact with one another and have a high mortality via predation
C)Female tigers that each inhabit their own large home range
D)Primates in a social group that frequently interact with the same individuals

Question 6

Consider Trivers's parent-offspring conflict model.How do you expect the zone of conflict between parent and offspring to differ when the future offspring is a half instead of a full sibling?

A)The zone of conflict will become wider.
B)The zone of conflict will become narrower.
C)The zone of conflict will remain of the same width but shift toward higher parental investment.
D)The zone of conflict will become wider and shift toward higher parental investment.

Question 7

In order for a game to be a true prisoner's dilemma,which of the following conditions must be met? P = Punishment for mutual defection,R = Reward for mutual cooperation,S = "Sucker's" payoff,T = Temptation to defect

A)T > R > P > S
C)R > P > S > T
B)S > P > T > R
D)R > P > T > S

Question 8

Consider the modified pay-off structure for the hawk-dove game below.What strategy should the players adopt? (v = benefit of the resource that is being fought over.)

A)Both players should either always play dove or always play hawk.
B)Both players should always play hawk.
C)One player should always play hawk; the other should always play dove.
D)Each player should play hawk a fraction of the time.

Question 9

Is haplodiploidy a necessary condition for the evolution of eusociality?

A)Yes, true eusociality is found only in the hymenoptera.
B)Yes, eusociality can only evolve when indirect fitness is as high as occurs between haplodiploid sisters.
C)No, true eusociality is also found in organisms that do not have a haplodiploid genetic system.
D)No, coefficients of relatedness between sisters are never 0.75 because there are always multiple fathers.

Question 10

Under what circumstance is there a mixed Nash equilibrium for the hawk-dove game?

A)When the cost of fighting equals the benefit of a victory
B)When the cost of fighting is greater than the benefit of a victory
C)When the strategy of the other player is unpredictable
D)When all members of the population play hawk exclusively

Question 11

What is the coefficient of relatedness for individuals A and B in the following pedigree?

A)0.5
B)0.25
C)0.125
D)0.0625

Question 12

Konrad Lorenz argued that "for the good of the species," animal fights are rarely lethal.Which of the following is the most compelling counter-argument to this assertion?

A)Animals of the same species rarely possess the physical means to kill each other.
B)Populations tend to produce more offspring than the carrying capacity of their environment, having individuals die in fights would be beneficial for the species.
C)Only humans can override the instinctual aversion to killing conspecifics.
D)An individual showing no restraint during fights would eliminate its competitors and maximize its individual fitness.

Question 13

An evolutionarily stable strategy (ESS)is a

A)strategy that, if adopted by all members of the population, cannot be invaded by a mutant strategy.
B)strategy that, if adopted by part of a population, cannot be invaded by a mutant strategy.
C)mutant strategy that cannot invade a population.
D)strategy that, if adopted by all members of the population, can be invaded by a mutant strategy.

Question 14

Researchers manipulated the tail length in male widowbirds and compared female preferences for males with different tail lengths.Do the results illustrated in the figure below show that male tail length is an honest signal of male quality?

A)Yes, otherwise females would not prefer males with longer tails.
B)Yes, the longer the tail the more energy males need to spend on growing it.
C)No, just putting a longer tail on a male does not increase its quality.
D)No, this study did not test whether birds with naturally long tails were of higher quality than birds with naturally short tails.

Question 15

Which of the following represents a Nash equilibrium in the hawk-dove game? Assume that the cost of a fight is greater than the benefit of the resource that is being fought over.

A)Both players always play dove.
B)Both players always play hawk.
C)Player 1 always plays hawk, player 2 always plays dove; both players know each other's role (player 1 or player 2) before the encounter.
D)Player 1 always plays hawk, while player 2 plays hawk some of the time and dove some of the time.

Question 16

In an analysis of independent contrast,researchers found that fetuses in polyandrous species of primates had faster growth rates than those in monogamous species.What did the researchers conclude from these results?

A)Fetuses develop faster to "make room" for offspring from a different male.
B)Extracting more resources from the mother maximizes offsprings' inclusive fitness in polyandrous species.
C)Fast fetal growth rates are always optimal.
D)Fetal growth rates represent phylogenetic constraints and are unrelated to mating systems.

Question 17

The model below predicts that the begging level of full offspring (F)should essentially be zero,whereas hungry (H)and starving (S)offspring show intermediate and high levels of begging,respectively.Under what circumstances would we expect full offspring to start begging?

A)When the fitness costs of begging are higher.
B)When the fitness costs of begging are lower.
C)Only when the fitness costs of begging increase in a nonlinear fashion with begging level.
D)Under no circumstances; the full (F) individuals are by definition at begging level zero.

Question 18

The results of Tibbetts and Izzo's experiment on facial patterns and the fighting behavior of the wasps are shown below.Why did Tibbetts and Izzo manipulate the wasps' aggressiveness,in addition to facial pattern?

A)To test whether hormones could artificially alter the fighting qualities of wasps
B)To test whether alteration of facial patterns strengthens the fighting ability of wasps
C)To test whether the alteration of facial patterns would result in increased aggression
D)To test whether the facial pattern is a conventional signal that is kept honest by continuous testing from conspecifics

Question 19

Compared to most physical resources,how is information unique?

A)There is no cost associated with sharing information.
B)The production and sharing of information does not require energy.
C)Because information is not a tangible physical entity, it does not affect an individual's fitness.
D)Information does not become depleted by sharing.

Question 20

Why was Charles Darwin initially puzzled by the observation that worker honey bees die when they sting an intruder to their hive? (The bee's stinger is ripped from the bee's abdomen,causing a fatal injury.)

A)All defensive behaviors result in the guaranteed destruction of the defender.
B)Such self-sacrifice is widespread in many different groups of animals.
C)He found it hard to imagine how such behavior could evolve, since a defending worker's chance of survival is zero.
D)The stinging apparatus appeared to be too complex to have evolved.

Question 21

Name the three familial conflicts.

Question 22

Allele X codes for a cooperative behavior among full siblings.Recipients of this behavior receive a benefit of 7 fitness units,and the behavior costs the donor 3 fitness units.Use Hamilton's rule to determine whether allele X will spread in the population.

Question 23

Describe the control in Tibbetts and Izzo's experiment,illustrated below,in which they manipulated the facial pattern and fighting behavior of wasps.

Question 24

Why does conflict arise between different alleles at the same locus even though they are part of a single individual's genome?

Question 25

Based on the figures below,calculate the coefficient of relatedness for individuals A and B in each case.Show your calculations.

Question 26

You want to study whether reciprocity explains the evolution of mobbing behavior in birds.You have two sources of birds to choose from: (A)a group of birds from your lab that all originated from the same mating pair,and (B)a group of presumably unrelated birds from the wild.Which choice would you prefer? Briefly justify your answer.

Question 27

Imagine you are studying horns in male deer,and you hypothesize that horns are costly honest signals that help to prevent male fights.What three predictions should you use to test your hypothesis?

Question 28

What gametes will survive after meiosis of the following chromosome pair? Sd = active segregation distorter allele,Sd⁺ = inactive segregation distorter allele,Rspˢ = response sensitive responder gene allele,Rspᶦ = response insensitive responder genes allele.

Question 29

Between which amounts of parental investment can you find the "zone of conflict" between parent and focal offspring? Delineate the "zone of conflict" in the figure below,and briefly explain how you chose the lower and upper bound.

Question 30

Assume that the cost of fighting is four times greater than the benefit gained from the resource that is being fought over.What is the probability with which an individual should play dove in the mixed Nash equilibrium of the hawk-dove game?

Question 31

Calculate the coefficient of relatedness for the following relationships in a haplodiploid hymenopteran species:

A)Sister to full sisters
B)Sister to brother
C)Brother to sister