Question 1

Natural selection favors sperm competition when

Accepted Answer

A)  males are clones with no genetic variation among sperm. 
B)  genetic mutation results in a greater chance of sperm fertilizing the female's eggs. 
C)  sperm decrease the fitness of a male. 
D)  all of the above 
A)  males are clones with no genetic variation among sperm. 
B)  genetic mutation results in a greater chance of sperm fertilizing the female's eggs. 
C)  sperm decrease the fitness of a male. 
D)  all of the above B

Question 2

Compare the three hypotheses that explain the indirect benefit of female mate choice.

Accepted Answer

The three hypotheses that explain the indirect benefit of female mate choice are the good genes hypothesis, the compatible genes hypothesis, and the direct benefits hypothesis.

The good genes hypothesis suggests that females choose mates based on traits that indicate genetic quality, such as physical attractiveness or strong immune systems. By choosing a mate with these traits, females can ensure that their offspring inherit these beneficial genes, leading to increased survival and reproductive success.

The compatible genes hypothesis proposes that females choose mates with genetic compatibility, meaning that their genes complement each other and result in healthier offspring. This can lead to increased genetic diversity and reduced risk of genetic disorders in the offspring.

The direct benefits hypothesis suggests that females choose mates based on the immediate benefits they can provide, such as food, protection, or parental care. By selecting a mate that can provide these resources, females can increase the survival and reproductive success of their offspring.

Overall, these three hypotheses provide different explanations for the indirect benefits of female mate choice, and each may play a role in shaping mating behavior and reproductive success in different species.

Question 3

Which of the following does not support the hypothesis that the evolution of parasites and hosts occurs in cycles?

Accepted Answer

A)  When parasites strike the most common genotypes in the population of their hosts, the hosts reproduce less or even die off. 
B)  When parasites strike the most common genotypes in the population of their hosts, more resistant host genotypes become more common. 
C)  When host genotypes become more common, the most common parasite is no longer well adapted to the most common host genotype. 
D)  Parasite genotypes are unable to exploit new host genotypes, so the cycle of parasite-host relationships ends. 
A)  When parasites strike the most common genotypes in the population of their hosts, the hosts reproduce less or even die off. 
B)  When parasites strike the most common genotypes in the population of their hosts, more resistant host genotypes become more common. 
C)  When host genotypes become more common, the most common parasite is no longer well adapted to the most common host genotype. 
D)  Parasite genotypes are unable to exploit new host genotypes, so the cycle of parasite-host relationships ends. D

Question 4

You are studying the potential for sexual conflict in two species of birds. Species 1 is monogamous, whereas species 2 is polygamous. In which species would sexual conflict likely be stronger?

Accepted Answer

Sexual conflict arises when the reproduc

Question 5

Which of the following supports sexual conflict as the selective factor shaping the reproductive organs of ducks?

Accepted Answer

A)  About one-third of all matings are forced. 
B)  Females drown from male harassment. 
C)  Males and females form pair bonds during the breeding season. 
D)  a and b 
E)  b and c 
A)  About one-third of all matings are forced. 
B)  Females drown from male harassment. 
C)  Males and females form pair bonds during the breeding season. 
D)  a and b 
E)  b and c

Question 6

Explain the difference between direct and indirect benefits of female mate choice.

Accepted Answer

Direct benefits of female mate choice re

Question 7

Ivy and Sakaluk (2005) studied the potential benefits of polyandry in decorated crickets. Their experimental design involved the following treatments: (1) females that mated a single time, (2) females that mated three times to a single male, and (3) females that mated with three different males. They measured offspring number and offspring survival for each treatment. How does this experimental design allow the researchers to differentiate between the potential benefits of polyandry?

Accepted Answer

The experimental design by Ivy and Sakal

Question 8

Which of the following is an example of polygyny?

Accepted Answer

A)  Male and female poison dart frogs remain loyal after picking a mate. 
B)  Male elephant seals mate with many females. 
C)  Female wattled jacanas may mate with several males. 
D)  Male and female bonobos do not form pair bonds during mating. 
A)  Male and female poison dart frogs remain loyal after picking a mate. 
B)  Male elephant seals mate with many females. 
C)  Female wattled jacanas may mate with several males. 
D)  Male and female bonobos do not form pair bonds during mating.

Question 9

In the case of red-collared widowbirds, what evidence suggests that the elaborately long tail of males is an honest signal?

Accepted Answer

A)  Males with the longest tails end up with three times more nesting females in their territories than short-tailed birds. 
B)  The tail comes at a cost because it increases drag during flight. 
C)  Males with long tails cannot hold their territories. 
D)  The tail is a fake symbol and does not imply good genes. 
A)  Males with the longest tails end up with three times more nesting females in their territories than short-tailed birds. 
B)  The tail comes at a cost because it increases drag during flight. 
C)  Males with long tails cannot hold their territories. 
D)  The tail is a fake symbol and does not imply good genes.

Question 10

In general, when sexual selection is strong for one sex and weak for the other, we can predict that members of the sex subject to strong sexual selection will be ________, and members of the sex subject to weak sexual selection will be ________.

Accepted Answer

A)  choosy; competitive 
B)  aggressive; passive 
C)  competitive; showy 
D)  competitive; choosy 
A)  choosy; competitive 
B)  aggressive; passive 
C)  competitive; showy 
D)  competitive; choosy

Question 11

Some species of male water striders forcibly copulate with females. In these species, males are often equipped with exaggerated grasping structures, while females have structures that obstruct the male's grip. Such a situation could arise through

Accepted Answer

A)  the Zahavi principle. 
B)  sensory bias. 
C)  intrasexual selection. 
D)  antagonistic coevolution. 
A)  the Zahavi principle. 
B)  sensory bias. 
C)  intrasexual selection. 
D)  antagonistic coevolution.

Question 12

According to sexual selection theory, a male signal is likely to be honest if

Accepted Answer

A)  it exploits a preexisting sensory bias in females. 
B)  it is condition-dependent. 
C)  it is costly to produce. 
D)  a and b 
E)  b and c 
A)  it exploits a preexisting sensory bias in females. 
B)  it is condition-dependent. 
C)  it is costly to produce. 
D)  a and b 
E)  b and c

Question 13

Explain three different mechanisms of sexual selection that occur after copulation, giving an example of each.

Accepted Answer

1) Sperm competition: After copulation,

Question 14

Polygyny is a good strategy for males because

Accepted Answer

A)  males can produce sperm cheaply, allowing them to fertilize many females. 
B)  males have to compete for access to females. 
C)  females control which sperm they use to fertilize their eggs. 
D)  all of the above 
A)  males can produce sperm cheaply, allowing them to fertilize many females. 
B)  males have to compete for access to females. 
C)  females control which sperm they use to fertilize their eggs. 
D)  all of the above

Question 15

Males of some species have proteins in their ejaculate that cause the female to be less attractive to other males for some period of time. Such a trait probably evolved initially through ________ but could also lead to ________ if remating is beneficial for females.

Accepted Answer

A)  male-male competition; sexual conflict and antagonistic coevolution 
B)  male-male competition; female choice 
C)  female choice; sexual conflict and antagonistic coevolution 
D)  runaway selection; female choice 
A)  male-male competition; sexual conflict and antagonistic coevolution 
B)  male-male competition; female choice 
C)  female choice; sexual conflict and antagonistic coevolution 
D)  runaway selection; female choice

Question 16

Which of the following is not a cost of sexual reproduction?

Accepted Answer

A)  Meiosis produces recombinant chromosomes, creating gametes with unique combinations of alleles. 
B)  Males and females must locate each other in order to mate. 
C)  Only half of an individual's alleles are passed on to their offspring. 
D)  Infections can be transmitted sexually. 
A)  Meiosis produces recombinant chromosomes, creating gametes with unique combinations of alleles. 
B)  Males and females must locate each other in order to mate. 
C)  Only half of an individual's alleles are passed on to their offspring. 
D)  Infections can be transmitted sexually.

Question 17

The graph below shows the reproductive success for males of two different species as a function of the number of mates they obtain. For which species would you expect sexual selection on males to be stronger?

Accepted Answer

A)  species 2; males of species 2 are expected to compete less strongly over access to females 
B)  species 1; males of species 1 are expected to compete less over access to females 
C)  species 2; males of species 2 are expected to compete more strongly over access to females 
D)  species 1; males of species 1 are expected to compete more strongly over access to females 
A)  species 2; males of species 2 are expected to compete less strongly over access to females 
B)  species 1; males of species 1 are expected to compete less over access to females 
C)  species 2; males of species 2 are expected to compete more strongly over access to females 
D)  species 1; males of species 1 are expected to compete more strongly over access to females

Question 18

Peahens prefer peacocks with more eyespots on their tail feathers. Which hypothesis do the results depicted in the graph below support?

Accepted Answer

A)  sensory bias hypothesis 
B)  arbitrary choice hypothesis 
C)  good genes hypothesis 
D)  good parent hypothesis 
A)  sensory bias hypothesis 
B)  arbitrary choice hypothesis 
C)  good genes hypothesis 
D)  good parent hypothesis

Question 19

All of the following are true of mate guarding except that it is:

Accepted Answer

A)  exclusive to a type of mating system. 
B)  males using toxic chemicals to create an inhospitable environment for females. 
C)  lingering males that chase off other males. 
D)  physical blockage of the female reproductive tract with giant sperm. 
A)  exclusive to a type of mating system. 
B)  males using toxic chemicals to create an inhospitable environment for females. 
C)  lingering males that chase off other males. 
D)  physical blockage of the female reproductive tract with giant sperm.

Question 20

Muller's ratchet is the idea that ________ accumulate in asexual populations. In such a situation, sex would be beneficial because ________.

Accepted Answer

A)  deleterious mutations; mutation-free genotypes could form through recombination 
B)  deleterious mutations; it provides protection against parasitism 
C)  deleterious mutations; more offspring would be produced and thus some are likely to survive 
D)  beneficial mutations; it would rapidly bring together beneficial mutations from different individuals 
E)  beneficial mutations; it would increase genetic diversity 
A)  deleterious mutations; mutation-free genotypes could form through recombination 
B)  deleterious mutations; it provides protection against parasitism 
C)  deleterious mutations; more offspring would be produced and thus some are likely to survive 
D)  beneficial mutations; it would rapidly bring together beneficial mutations from different individuals 
E)  beneficial mutations; it would increase genetic diversity

Natural selection favors sperm competition when

Compare the three hypotheses that explain the indirect benefit of female mate choice.

Which of the following does not support the hypothesis that the evolution of parasites and hosts occurs in cycles?

You are studying the potential for sexual conflict in two species of birds. Species 1 is monogamous, whereas species 2 is polygamous. In which species would sexual conflict likely be stronger?

Which of the following supports sexual conflict as the selective factor shaping the reproductive organs of ducks?

Explain the difference between direct and indirect benefits of female mate choice.

Which of the following is an example of polygyny?

In the case of red-collared widowbirds, what evidence suggests that the elaborately long tail of males is an honest signal?

In general, when sexual selection is strong for one sex and weak for the other, we can predict that members of the sex subject to strong sexual selection will be , and members of the sex subject to weak sexual selection will be .

Some species of male water striders forcibly copulate with females. In these species, males are often equipped with exaggerated grasping structures, while females have structures that obstruct the male's grip. Such a situation could arise through

According to sexual selection theory, a male signal is likely to be honest if

Explain three different mechanisms of sexual selection that occur after copulation, giving an example of each.

Polygyny is a good strategy for males because

Males of some species have proteins in their ejaculate that cause the female to be less attractive to other males for some period of time. Such a trait probably evolved initially through but could also lead to if remating is beneficial for females.

Which of the following is not a cost of sexual reproduction?

The graph below shows the reproductive success for males of two different species as a function of the number of mates they obtain. For which species would you expect sexual selection on males to be stronger?

Peahens prefer peacocks with more eyespots on their tail feathers. Which hypothesis do the results depicted in the graph below support?

All of the following are true of mate guarding except that it is:

Muller's ratchet is the idea that accumulate in asexual populations. In such a situation, sex would be beneficial because .

The Whale and the Virus: How Scientists Study Evolution

From Natural Philosophy to Darwin: a Brief History of Evolutionary Ideas

What the Rocks Say: How Geology and Paleontology Reveal the History of Life

The Tree of Life: How Biologists Use Phylogeny to Reconstruct the Deep Past

Raw Material: Heritable Variation Among Individuals

The Ways of Change: Drift and Selection

Beyond Alleles: Quantitative Genetics and the Evolution of Phenotypes

The History in Our Genes

From Genes to Traits: the Evolution of Genetic Networks and Development

Natural Selection: Empirical Studies in the Wild

After Conception: the Evolution of Life History and Parental Care

The Origin of Species

Macroevolution: the Long Run

Intimate Partnerships: How Species Adapt to Each Other

Brains and Behavior

Human Evolution: a New Kind of Ape

Evolutionary Medicine

Filters

Exam 11: Sex: Causes and Consequences

Natural selection favors sperm competition when

Compare the three hypotheses that explain the indirect benefit of female mate choice.

Which of the following does not support the hypothesis that the evolution of parasites and hosts occurs in cycles?

You are studying the potential for sexual conflict in two species of birds. Species 1 is monogamous, whereas species 2 is polygamous. In which species would sexual conflict likely be stronger?

Which of the following supports sexual conflict as the selective factor shaping the reproductive organs of ducks?

Explain the difference between direct and indirect benefits of female mate choice.

Which of the following is an example of polygyny?

In the case of red-collared widowbirds, what evidence suggests that the elaborately long tail of males is an honest signal?

In general, when sexual selection is strong for one sex and weak for the other, we can predict that members of the sex subject to strong sexual selection will be ________, and members of the sex subject to weak sexual selection will be ________.

Some species of male water striders forcibly copulate with females. In these species, males are often equipped with exaggerated grasping structures, while females have structures that obstruct the male's grip. Such a situation could arise through

According to sexual selection theory, a male signal is likely to be honest if

Explain three different mechanisms of sexual selection that occur after copulation, giving an example of each.

Polygyny is a good strategy for males because

Males of some species have proteins in their ejaculate that cause the female to be less attractive to other males for some period of time. Such a trait probably evolved initially through ________ but could also lead to ________ if remating is beneficial for females.

Which of the following is not a cost of sexual reproduction?

The graph below shows the reproductive success for males of two different species as a function of the number of mates they obtain. For which species would you expect sexual selection on males to be stronger?

Peahens prefer peacocks with more eyespots on their tail feathers. Which hypothesis do the results depicted in the graph below support?

All of the following are true of mate guarding except that it is:

Muller's ratchet is the idea that ________ accumulate in asexual populations. In such a situation, sex would be beneficial because ________.

The Whale and the Virus: How Scientists Study Evolution

From Natural Philosophy to Darwin: a Brief History of Evolutionary Ideas

What the Rocks Say: How Geology and Paleontology Reveal the History of Life

The Tree of Life: How Biologists Use Phylogeny to Reconstruct the Deep Past

Raw Material: Heritable Variation Among Individuals

The Ways of Change: Drift and Selection

Beyond Alleles: Quantitative Genetics and the Evolution of Phenotypes

The History in Our Genes

From Genes to Traits: the Evolution of Genetic Networks and Development

Natural Selection: Empirical Studies in the Wild

After Conception: the Evolution of Life History and Parental Care

The Origin of Species

Macroevolution: the Long Run

Intimate Partnerships: How Species Adapt to Each Other

Brains and Behavior

Human Evolution: a New Kind of Ape

Evolutionary Medicine

Filters

In general, when sexual selection is strong for one sex and weak for the other, we can predict that members of the sex subject to strong sexual selection will be , and members of the sex subject to weak sexual selection will be .

Males of some species have proteins in their ejaculate that cause the female to be less attractive to other males for some period of time. Such a trait probably evolved initially through but could also lead to if remating is beneficial for females.

Muller's ratchet is the idea that accumulate in asexual populations. In such a situation, sex would be beneficial because .