What is "genetic drift"?

Genetic drift is indeed a mechanism of evolution characterized by random changes in allele frequencies within a population. This phenomenon occurs due to chance events, leading to fluctuations in allele frequencies from one generation to the next. It is particularly significant in small populations, where random events can have a more pronounced effect on the genetic makeup of the population compared to larger populations.

In contrast to other evolutionary mechanisms such as natural selection, which is a non-random process that results in adaptive changes based on environmental pressures, genetic drift operates without regard to the adaptive value of the alleles. This randomness can result in the loss of genetic variation, as alleles can be lost entirely from the population simply by chance.

This understanding highlights the importance of population size in the effects of genetic drift; in smaller populations, allele frequencies can change rapidly and unpredictably, which can lead to significant evolutionary consequences over time. This clarifies why statements regarding selective breeding, the occurrence solely in large populations, or the theory’s application only to plants do not accurately depict genetic drift.