Two populations of mice exist on either side of a river. After a bridge is constructed across the river, the two populations come to resemble each other more.

What is the most likely explanation for this?

A) Stabilizing selection

B) Directional selection

C) Gene flow

D) Genetic drift

E) Nonrandom mating

C) Gene flow

Explanation:

Gene flow refers to the movement of alleles between local populations. It results from the migration of individuals. Two adjacent populations can exhibit gene flow due to the mating between their individuals and can have significant evolutionary consequences as it does not allow the reproductive isolation of these populations. In the given example, the two mice populations are present on either side of a river. Mating between the mice of the two populations resulted in gene flow and maintained resemblance among their members.