In eastern gray squirrels, sciurus carolinensis, the allele for black fur (b) is dominant to the allele for gray fur (b). in a particular population of gray squirrels, 64% have black fur and 36% have gray fur. a researcher calculated the allelic frequencies to be b=0.4 and b=0.6. five years later, the researcher returned to the location and determined the allelic frequencies within the squirrel population to be b=0.6 and b=0.4

The correct answer is "The frequency of the B allele increased due to the selective pressures of the environment".

Explanation:

The missing part of the question is "Which of the following could best explain the increase in the frequency of the B allele in the population after five years?" at which the answer is "The frequency of the B allele increased due to the selective pressures of the environment".

In this study, the allelic frequency for black fur (B) in eastern gray squirrels Sciurus carolinensis changed from B=0.4 to B=0.6 within a lapse of five years. This increase is explained by the effect of selective pressures of the environment. For instance, is likely that new predators were more likely to detect squirrels with gray fur over black fur, or changes in the landscape benefited the black fur squirrels camouflage.