Deck 12: Principles of Social Evolution

Question 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 1

D

Question 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 2

C

Question 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 3

A

Question 4

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 direct fitness cost to the male for his alarm-calling altruism?

A) 0
B) 0.25
C) 1.5
D) 1.75

Question 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 for his alarm-calling altruism?

A) 0
B) 0.25
C) 1.5
D) 1.75

Question 6

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 inclusive fitness of this individual?

A) 0
B) 0.25
C) 1.5
D) 1.75

Question 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. 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 the indirect fitness cost of the behavior was lower than the direct fitness benefit.
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 no direct fitness benefit is not adaptive.

Question 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, George 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.

Question 9

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. What was Bob's cost to himself in units of direct fitness (such as children)?

A) 1
B) 1.5
C) 2
D) 3

Question 10

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. What was Bob's benefit to himself in units of indirect fitness (such as children)?

A) 0.5
B) 0.75
C) 1.5
D) 3

Question 11

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. According to Hamilton's rule, Bob's decision was

A) adaptive.
B) maladaptive.
C) adaptable.
D) adaptationist.

Question 12

One of the main benefits ascribed to using multilevel selection to explain the evolution of complex social behavior is that it

A) combines individual- and group-level selection into a single framework.
B) provides a more accurate calculation of the contribution of alleles to the next generation.
C) produces clear and testable hypotheses to understand the evolution of social behaviors.
D) can be used to understand the evolution of eusociality.

Question 13

One of the main benefits ascribed to using inclusive fitness theory to explain the evolution of complex social behavior is that it

A) combines individual- and group-level selection into a single framework.
B) provides a more accurate calculation of the contribution of alleles to the next generation.
C) produces clear and testable hypotheses to understand the evolution of social behaviors.
D) can be used to understand the evolution of eusociality.

Question 14

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.

Question 15

Refer to the figure.
These results demonstrate that

A) policing behavior of workers increases the reproductive skew between queens.
B) workers with higher degrees of relatedness exhibit less effective policing behavior.
C) the better workers are at policing, the less workers are able to gain direct fitness.
D) queen overproduction is more likely to occur in colonies with low policing and a large number of workers' sons.

Question 16

Refer to the figure.
These results indicate that

A) polyandry evolved from a single common ancestor.
B) the ancestral species of each eusocial group was monogamous.
C) altruism only occurs in polyandrous species.
D) haplodiploidy inheritance explains the evolution of eusociality.

Question 17

Refer to the figure.
What hypothesis do these results support?

A) The monogamy hypothesis for the evolution of eusociality.
B) The haplodiploidy hypothesis for the evolution of eusociality.
C) The kin selection hypothesis for the evolution of altruism.
D) The group selection hypothesis for the evolution of altruism.

Question 18

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

Question 19

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?

Question 20

Compare the monogamy hypothesis and the haplodiploidy hypothesis for the evolution of eusociality. Describe one prediction for each hypothesis.