Question

What happens once a population undergoing directional selection reaches its new optimum phenotype?

Options

• Internal competition increases, eliminating intermediate phenotypes.

• Disruptive selection splits the population into two distinct groups.

• Stabilising selection takes over to maintain the new phenotype.

• Directional selection reverses its course toward the opposite extreme.

Answer 1

Directional selection exerts pressure that shifts the mean phenotype toward one specific extreme. Once the new phenotypic optimum is reached, stabilising selection takes over to maintain it.