Question

The mode of natural selection in which extreme phenotypes are less fit than the optimal intermediate phenotype is

A. directional selection.
B. disruptive selection.
C. stabilizing selection.
D. artificial selection.
E. uniformitarianism.

Answer 1

Stabilizing selection is the type of natural selection where intermediate phenotypes are favored over extreme ones, leading to reduced genetic variance within a population.

Step-by-step explanation:

The mode of natural selection where extreme phenotypes are less fit compared to the intermediate phenotype is known as stabilizing selection. This form of selection typically occurs when the environment stabilizes and favors an intermediate phenotype over more extreme variations, thus decreasing the population's genetic variance. For example, in the case of human birth weight, both very large and very small babies are less likely to survive compared to babies with an intermediate weight, leading to a narrower range of birth weights within the population over time.