Question 1

Which of the following is NOT a reason why the twofold cost of sex is sometimes referred to as the "cost of males"?

Accepted Answer

A)  Males do not contribute genes to the next generation. 
B)  Males do not produce new offspring. 
C)  Males invest in sperm, most of which are wasted, rather than biomass. 
D)  Sperm cells do not contribute any substantial energy resources to the eggs they fertilize. 
A)  Males do not contribute genes to the next generation. 
B)  Males do not produce new offspring. 
C)  Males invest in sperm, most of which are wasted, rather than biomass. 
D)  Sperm cells do not contribute any substantial energy resources to the eggs they fertilize.

Question 2

Which of the following is NOT a problem associated with distinguishing the Fisherian sexual selection model from the good genes model?

Accepted Answer

A)  Neither the good genes model nor the Fisher model predict a positive correlation between male ornamentation and male viability. 
B)  The Fisher process operates on top of any good genes mechanism. 
C)  Linkage disequilibrium between female preference and a male trait is predicted by both models. 
D)  Neither model accounts for the effects of runaway sexual selection, which reinforces linkage disequilibrium. 
A)  Neither the good genes model nor the Fisher model predict a positive correlation between male ornamentation and male viability. 
B)  The Fisher process operates on top of any good genes mechanism. 
C)  Linkage disequilibrium between female preference and a male trait is predicted by both models. 
D)  Neither model accounts for the effects of runaway sexual selection, which reinforces linkage disequilibrium.

Question 3

Describe the three-step process of amphimixis.

Accepted Answer

Recombination occurs as a result of cros

Question 4

Would there be any disadvantage of sex if sexual reproduction was isogamous?

Accepted Answer

A)  No; females would not pay the twofold cost of sex. 
B)  Yes; sex may break up coadapted gene complexes. 
C)  No; females would still transmit the same proportion of their genes to the next generation. 
D)  Yes; isogamous parents contribute unequally to gamete production, resulting in one parent experiencing a greater cost of reproduction. 
A)  No; females would not pay the twofold cost of sex. 
B)  Yes; sex may break up coadapted gene complexes. 
C)  No; females would still transmit the same proportion of their genes to the next generation. 
D)  Yes; isogamous parents contribute unequally to gamete production, resulting in one parent experiencing a greater cost of reproduction.

Question 5

In a population that is polymorphic for sexual/asexual reproduction, a sexually transmitted disease has just eliminated most of the sexually reproducing individuals. When you expose samples of asexuals and sexuals from this population to harsh environmental conditions in the lab, you discover that the sexual individuals are worse at adapting to the new environment than the asexual individuals. (Note that your lab population is free from the sexually transmitted disease.) Which of the following statements is a likely explanation for your results?

Accepted Answer

A)  All asexually reproducing strains independently acquired the same beneficial mutation that offset the advantage of the sexuals. 
B)  The bottleneck caused by the disease resulted in the fixation of many alleles in the sexually reproducing population. 
C)  Asexuals are favored under harsh environmental conditions. 
D)  The results support standard evolutionary theory. 
A)  All asexually reproducing strains independently acquired the same beneficial mutation that offset the advantage of the sexuals. 
B)  The bottleneck caused by the disease resulted in the fixation of many alleles in the sexually reproducing population. 
C)  Asexuals are favored under harsh environmental conditions. 
D)  The results support standard evolutionary theory.

Question 6

Which of the following statements describes an element of the Fisher-Muller hypothesis for adaptive advantage of sexual reproduction?

Accepted Answer

A)  Sex builds up linkage disequilibrium. 
B)  Sex slows down adaptive evolution by disrupting coadapted gene complexes. 
C)  Sex facilitates the combination of favorable mutations that originated in different individuals into advantageous genotypes. 
D)  Sex can increase the frequency of deleterious mutations. 
A)  Sex builds up linkage disequilibrium. 
B)  Sex slows down adaptive evolution by disrupting coadapted gene complexes. 
C)  Sex facilitates the combination of favorable mutations that originated in different individuals into advantageous genotypes. 
D)  Sex can increase the frequency of deleterious mutations.

Question 7

Why is sexual reproduction believed to be the ancestral state in eukaryotes?

Accepted Answer

A)  Asexual reproduction is completely absent from basal unicellular eukaryotes. 
B)  Under the parsimony principle, the most common form of a trait's state is always the ancestral state. 
C)  The "twiggy" distribution of obligate asexual reproduction in phylogenetic trees suggests that asexuality is a derived trait. 
D)  Evolutionary models suggest that obligate asexual taxa are more prone to extinction than sexual ones. 
A)  Asexual reproduction is completely absent from basal unicellular eukaryotes. 
B)  Under the parsimony principle, the most common form of a trait's state is always the ancestral state. 
C)  The "twiggy" distribution of obligate asexual reproduction in phylogenetic trees suggests that asexuality is a derived trait. 
D)  Evolutionary models suggest that obligate asexual taxa are more prone to extinction than sexual ones.

Question 8

Under what conditions are asexual and sexual reproduction favored by the three evolutionary models shown in the figure, involving environmental unpredictability, number of niches, and parasite load? State whether a high or low value for each condition will favor sexual or asexual reproduction.   A) Low environmental unpredictability
B) High environmental unpredictability
C) Low number of niches
D) High number of niches
E) Low parasite load
F) High parasite load

Accepted Answer

Low values for each condition

Question 9

Why is male reproductive success limited by the number of eggs?

Accepted Answer

A)  Sperm are short lived compared to eggs and it is more expensive for males to reproduce because males produce a much greater number of gametes than there are eggs available to fertilize. 
B)  Eggs are much larger and scarcer than sperm, limiting the number of opportunities for reproductive success for males. 
C)  Eggs are smaller than sperm and short lived, limiting the number of opportunities for reproductive success for males. 
D)  Although eggs are not metabolically expensive to produce, most female organisms will only produce a small number of eggs during their life span. 
A)  Sperm are short lived compared to eggs and it is more expensive for males to reproduce because males produce a much greater number of gametes than there are eggs available to fertilize. 
B)  Eggs are much larger and scarcer than sperm, limiting the number of opportunities for reproductive success for males. 
C)  Eggs are smaller than sperm and short lived, limiting the number of opportunities for reproductive success for males. 
D)  Although eggs are not metabolically expensive to produce, most female organisms will only produce a small number of eggs during their life span.

Which of the following is NOT a reason why the twofold cost of sex is sometimes referred to as the "cost of males"?

Which of the following is NOT a problem associated with distinguishing the Fisherian sexual selection model from the good genes model?

Describe the three-step process of amphimixis.

Would there be any disadvantage of sex if sexual reproduction was isogamous?

Which of the following statements describes an element of the Fisher-Muller hypothesis for adaptive advantage of sexual reproduction?

Why is sexual reproduction believed to be the ancestral state in eukaryotes?

Why is male reproductive success limited by the number of eggs?

An Overview of Evolutionary Biology

Early Evolutionary Ideas and Darwin S Insight

Natural Selection

Phylogeny and Evolutionary History

Inferring Phylogeny

Transmission Genetics and the Sources of Genetic Variation

The Genetics of Populations

Evolution in Finite Populations

Evolution at Multiple Loci

Genome Evolution

The Origin and Evolution of Early Life

Major Transitions

Evolution and Development

Species and Speciation

Extinction and Evolutionary Trends

The Evolution of Sociality

Coevolution

Human Evolution

Evolution and Medicine

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Exam 16: The Evolution of Sex

Which of the following is NOT a reason why the twofold cost of sex is sometimes referred to as the "cost of males"?

Which of the following is NOT a problem associated with distinguishing the Fisherian sexual selection model from the good genes model?

Describe the three-step process of amphimixis.

Would there be any disadvantage of sex if sexual reproduction was isogamous?

Which of the following statements describes an element of the Fisher-Muller hypothesis for adaptive advantage of sexual reproduction?

Why is sexual reproduction believed to be the ancestral state in eukaryotes?

Why is male reproductive success limited by the number of eggs?

An Overview of Evolutionary Biology

Early Evolutionary Ideas and Darwin S Insight

Natural Selection

Phylogeny and Evolutionary History

Inferring Phylogeny

Transmission Genetics and the Sources of Genetic Variation

The Genetics of Populations

Evolution in Finite Populations

Evolution at Multiple Loci

Genome Evolution

The Origin and Evolution of Early Life

Major Transitions

Evolution and Development

Species and Speciation

Extinction and Evolutionary Trends

The Evolution of Sociality

Coevolution

Human Evolution

Evolution and Medicine

Filters