試題詳解

22. One population of a species has 25 individuals, all with genotype AA； a second population of this species has 40 individuals, all with genotype aa. Assume that these populations live far rt but in similar environmental conditions. Based on this information, the obs genetic variation most likely resulted from______.
(A)genetic drift
(B)gene flow
(C)nonrandom mating
(D)directional selection