What describes the change in allele frequency in a population due to random events rather than natural selection?

The correct response is genetic drift, which refers to the change in allele frequencies in a population caused by random sampling events. This phenomenon occurs especially in small populations, where chance events can lead to significant differences in allele frequencies from one generation to the next independently of adaptive traits.

For instance, if a small group of individuals in a population reproduces, their genetic makeup can disproportionately influence the next generation. Consequently, certain alleles may become more common or disappear entirely purely by chance. This randomness is what defines genetic drift and distinguishes it from processes like natural selection, where allele frequencies change in response to environmental pressures favoring certain traits.

In contrast, gene flow involves the transfer of alleles between populations, typically through migration, affecting allele frequencies but not randomly. Artificial selection results from human intervention in breeding, where specific traits are intentionally selected to persist, and migration refers to physical movement of individuals from one region to another, which can also alter allele frequencies but relies on movement rather than random chance.