Evolution Chapter 20 Discussion Questions

What has knowledge of genetics contributed to our understanding of evolution? (See also Chapter 1.)

What is meant by an adaptation? What evidence could be used to show that the following phenomena are adaptations?

• Flowers that smell of rotting meat.

• Nausea and vomiting in pregnancy (see Fig. 26.16).

• Genetic recombination.

In each case, suggest alternative nonadaptive explanations.

Many alleles that substantially increase lifespan have been discovered in model organisms. Why are such alleles surprising?

Male fitness is determined by competition between males for mates and by mating preferences of females. How can these be distinguished?

Describe three explanations for the evolution of female choice. How can these alternatives be tested?

What is the evidence that females can choose to mate with males that have “good genes”?