There Are 25 Individuals in Population 1, All with Genotype

Multiple Choice

There are 25 individuals in population 1, all with genotype AA, and there are 40 individuals in population 2, all with genotype aa. Assume that these populations are located far from each other and that their environmental conditions are very similar. Based on the information given here, the observed genetic variation most likely resulted from

A) genetic drift.
B) gene flow.
C) nonrandom mating.
D) directional selection.