14.4.2 Courtship and Mating Behaviors: Survivability

Question 1

Courtship and Mating Behaviors: Survivability

Answer 1

• According to Darwin, sexual selection differs from natural selection because the fittest mate is not necessarily the fittest individual.
• Analyzing cost/benefit ratios enables you to predict the viability of a trait or behavior relative to sexual selection.
• Regarding sexual selection, variation in traits and behaviors occurs at the level of the individual. Evolution occurs at the population level.

Question 2

sexual selection

Answer 2

• Review: Natural selection is the process by which advantages in survival result in greater reproductive success.
• Sexual selection is the process by which advantages in attracting or competing for mates result in differential
  reproductive success.
• Darwin theorized that sexual selection was different from natural selection because the fittest mate is not necessarily the fittest individual.

Question 3

courtship rituals

Answer 3

• consist of ritual displays by one or more
  members of the opposite sex. In most animal species, males do the posturing, and females do the selecting.
• By courting, a male demonstrates that mating with him will provide the selective advantage to the female’s genes, which will live on in healthy offspring.
• In some species of birds, bats, and insects, males gather in a group at an assembly area called a lek to display competitively for females.

Question 4

note

Answer 4

• Males and females have different costs and benefits associated with reproduction and offspring. Females can expend a great deal of energy in ovulation, gestation, and the rearing of young. Overall, males expend less energy, with most of their energy invested in courtship and display.
• It is predicted that females select males that offer a better cost/benefit ratio.

Question 5

In many animal populations the male actively courts the female. By performing courtship rituals, the male demonstrates that

Answer 5

• mating with him will provide a selective advantage to the female’s offspring.

Question 6

Which of the following are indicators to a female bird that a male bird will provide a good return on her parental investment?

Answer 6

• strength

- presentation of food

Question 7

____________ is the process in which advantages in attracting or competing for mates results in differential reproductive success.

Answer 7

• Sexual selection

Question 8

Sexual selection will lead to the evolution of traits that

Answer 8

• enhance the number of mates a male obtains.

Question 9

Variation in traits and behaviors occurs on the level of the ____________; evolution occurs at the ____________ level.

Answer 9

• individual; population

Question 10

In general, ____________ are responsible for mate selection and ____________ are involved in posturing behaviors.

Answer 10

• females; males

Question 11

If both parents contribute equal genetic material to an offspring, why is the female more discriminate than the male?

Answer 11

• The female needs to maximize her return on her greater parental investment in the offspring.

Question 12

What is a lek?

Answer 12

• An assembly area where animals display courtship behavior.