Genetic drift is change in allelic frequency due to chance factors. The amount of change in allelic frequency due to genetic drift is inversely related to the effective population size (the equivalent number of breeding adults in a population).
-Which of the following statements is an example of genetic drift?
A) Allele g for fat production increases in a small population because birds with more body fat have higher survivorship in a harsh winter.
B) Random mutation increases the frequency of allele A in one population but not in another.
C) Allele R reaches a frequency of 1.0 because individuals with genotype rr are sterile.
D) Allele m is lost when a virus kills all but a few individuals and just by chance none of the survivors possess allele m.

Question

Quizplus · Accepted Answer

Genetic drift involves random changes in allele frequencies, often having a more significant impact in small populations. In option D, the loss of allele m due to a random event (a virus) killing individuals is an example of genetic drift, as the survivors randomly do not carry allele m.

Genetic Drift Is Change in Allelic Frequency Due to Chance