Deck 9: Reproductive Behavior

Question 1

Male fifteen-spined sticklebacks that shake their body frequently when courting also provide more nest fanning of their eggs, and are preferred by females. This is an example of

A) direct benefits.
B) the good genes model of sexual selection.
C) the runaway selection model of sexual selection.
D) the chase-away selection model of sexual selection.

Answer 1

A

Question 2

Male satin bowerbirds that build well-constructed bowers also perform better on cognitive tests, and have higher mating success. This is an example of

A) direct benefits.
B) the good genes model of sexual selection.
C) the runaway selection model of sexual selection.
D) the chase-away selection model of sexual selection.

Answer 2

B

Question 3

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 runaway selection model of sexual selection.
D) the chase-away selection model of sexual selection.

Answer 3

C

Question 4

Female fruit flies prefer to mate with large males. This mate choice lowers the female's longevity and reduces survival of her offspring. This is an example of

A) direct benefits.
B) the good genes model of sexual selection.
C) the runaway selection model of sexual selection.
D) the chase-away selection model of sexual selection.

Question 5

A male spider that amputates his own sperm-transferring pedipalps during copulation so as to block the female's genital opening is an example of

A) male-male competition.
B) cryptic female choice.
C) male parental investment.
D) runaway model of sexual selection.

Question 6

Female chicks eject a larger proportion of semen from low-ranking males than from high-ranking males. This is an example of

A) male-male competition.
B) cryptic female choice.
C) male parental investment.
D) runaway model of sexual selection.

Question 7

Refer to the figure.
Based on these results, which sex has greater reproductive variance?

A) Females
B) Males
C) Males and females are the same
D) Cannot be determined from the data

Question 8

Refer to the figure.
The graph on the right illustrates the concept of

A) parental investment.
B) sexual dimorphism.
C) anisogamy.
D) reproductive skew.

Question 9

Refer to the figure.
Based on these results, sexual selection pressure is likely higher on which sex?

A) Females
B) Males
C) Males and females are the same
D) Cannot be determined from the data

Question 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.

Question 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.

Question 12

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. This suggests that these three male sizes are an example of

A) a conditional mating tactic.
B) an alternating mating strategy.
C) intersexual selection.
D) cryptic female choice.

Question 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. 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.

Question 14

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 lower survival.
D) is similar to natural selection in that it acts on traits that increase an individual's relative reproductive success and survival.

Question 15

Why are females more likely to care for young than males in a non-sex role reversed species?

A) Male paternity is less certain than female paternity, and males gain more by mating with multiple partners.
B) Female reproductive success depends on maximizing both the number of mates and the number of offspring produced.
C) Females enhance their fitness more by investing in current offspring, while males enhance their fitness more by investing in future offspring.
D) Reproductive competition is highest in females, leading to stronger sexual selection for greater investment in parental care.

Question 16

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 larger and have ornaments to compete for mates.
D) sexual selection will be weaker than natural selection.

Question 17

Refer to the figure.
These results show that

A) species with male-biased operational sex ratios are more common.
B) female-biased operational sex ratios are more likely to occur in warmer environments.
C) the operational sex ratio shifts from male-biased to female-biased over the season.
D) there is higher mating success in males in the beginning of the season compared to the end of the season.

Question 18

Refer to the figure.
These findings illustrate

A) Bateman's principle, where males have higher reproductive variance than females due to sex differences in mating behavior.
B) that sex roles can be dynamic and shift over the course of a single breeding season.
C) female parental investment impacts the operational sex ratio during the breeding season.
D) that sex role reversal is more likely to occur in species in predictable environments.

Question 19

Refer to the figure.
Marion Petrie derived a number of predictions regarding the role of a male peacock's eyespots. Which prediction does this data most directly support?

A) Males should differ genetically in ways related to their survival chances.
B) Male behavior and ornamentation should provide accurate information on the survival value of the males' genes.
C) Females should use this information to select mates.
D) The offspring of the chosen males should benefit from their mother's mate choice.

Question 20

Refer to the figure.
Which model of sexual selection does this data support?

A) Direct benefits.
B) The good genes model of sexual selection.
C) The runaway selection model of sexual selection.
D) The chase-away selection model of sexual selection.

Question 21

Describe two direct benefits and one indirect benefit that females can gain by being choosy about their mate.

Question 22

Under what conditions would you predict sexual selection to act more strongly on female than male traits?

Question 23

Describe two ways that males compete with each other for females after they have already mated.

Question 24

Male bedbugs use a spear-like organ to stab females in the abdomen before injecting his sperm, leaving a wound and causing possible infections. How does this harmful male trait persist, despite its negative impact on female fitness? If this species is engaged in a sexual arms race, what prediction can we make about the female bedbug's physiology or behavior?