AP BIOLOGY

Detailed explanation-1: -The correct answer is A. Peahens choose to mate with peacocks that have the most beautiful tails. Sexual selection arises from differences in mating success when there is a preference by one sex for certain characteristics in individuals of the other sex.

Detailed explanation-2: -Males are usually the most colorful sex because females are more likely to be in short supply due to the extra work involved in incubation and chick rearing. Males must thus compete for the chance to mate with them.

Detailed explanation-3: -Which Sex is Under Stronger Selection? Sex roles are defined by differences in gametes: females produce relatively few, highly nutritious (usually non-motile) gametes, whereas males produce comparatively abundant, smaller, motile gametes.

Detailed explanation-4: -There are two general circumstances leading to sexual selection. One is the preference shown by one sex (often the females) for individuals of the other sex that exhibit certain traits. The other is increased strength (usually among the males) that yields greater success in securing mates.