Chapter 23: The evolution of populations (3)

Question 1

What is sexual selection?

Answer 1

Sexual selection is a form of selection in which individuals with certain inherited characteristics are more likely than other individuals to obtain mates.

Question 2

What can sexual selection result in?

Answer 2

Sexual selection can result in sexual dimorphism, a difference in secondary sexual characteristics between males and females of the same species.

Question 3

What are the two ways sexual selection operates?

Answer 3

Intrasexual and Intersexual selection.

Question 4

Define intrasexual selection.

Answer 4

In intrasexual selection, meaning selection within the same sex, individuals of one sex compete directly for mates of the opposite sex.

Question 5

Define intersexual selection.

Answer 5

In intersexual selection, also called mate choice, individuals of one sex (usually the females) are choosy in selecting their mates from the other sex.

Question 6

How do female preferences for certain male characteristics evolve in the first place?

Answer 6

One hypothesis is that females prefer
male traits that are correlated with “good genes.”

If the trait preferred by females is indicative of a male’s overall genetic quality, both the male trait and female preference for it should increase in frequency

Question 7

Define relative fitness.

Answer 7

Relative fitness defines as the measure on which how successful is the organism survive in an environment and how well it can pass its genes to the its offspring