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. Which of the following could best explain the increase in the frequency of the B allele in the population after five years? a) the frequency of the B allele increased because it is the dominant allele b) the frequency of the B allele is increased because squirrels with gray fur exhibit greater fitness c) the frequency of the B allele increased due to the selective pressures of the environment d) the frequency of the B allele increased because black squirrels randomly mate with other eastern gray squirrels
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. Which of the following could best explain the increase in the frequency of the B allele in the population after five years?
a) the frequency of the B allele increased because it is the dominant allele
b) the frequency of the B allele is increased because squirrels with gray fur exhibit greater fitness
c) the frequency of the B allele increased due to the selective pressures of the environment
d) the frequency of the B allele increased because black squirrels randomly mate with other eastern gray squirrels
Answer
Answer: c) the frequency of the B allele increased due to the selective pressures of the environment
Explanation: An increase in the frequency of the B allele suggests that selective pressures, such as environmental factors, may have favored black fur over gray fur, leading to an increase in the B allele’s frequency.
Sourav
