Genetic drift refers to what kind of changes in allele frequencies?

Genetic drift refers to what kind of changes in allele frequencies?

• A. Migration
• B. Random changes in allele frequencies due to sampling
• C. Mutation
• D. Change due to natural selection

Answer: (B)

Random fluctuations in allele frequencies from one generation to the next due to chance sampling during reproduction. In small populations, the individuals that reproduce represent only a sample of the gene pool, so some alleles can become more common and others can disappear purely by luck. Over time these random changes can lead to one allele fixing or being lost and generally reduce genetic variation. This differs from natural selection, where frequencies shift because certain variants confer a reproductive advantage; drift is about randomness in reproduction, not fitness.

Random fluctuations in allele frequencies from one generation to the next due to chance sampling during reproduction. In small populations, the individuals that reproduce represent only a sample of the gene pool, so some alleles can become more common and others can disappear purely by luck. Over time these random changes can lead to one allele fixing or being lost and generally reduce genetic variation. This differs from natural selection, where frequencies shift because certain variants confer a reproductive advantage; drift is about randomness in reproduction, not fitness.