What does genetic drift refer to in a population?

Genetic drift refers to the random changes in gene frequencies within a population, particularly in small populations where chance events can lead to significant shifts in allele frequencies from one generation to the next. This can occur through mechanisms such as the bottleneck effect, where a sudden reduction in population size leads to a loss of genetic diversity, or the founder effect, where a small group starts a new population and the genetic makeup of that group can influence the future generations.

In contrast to directed selection or stabilization, genetic drift is not a process influenced by the adaptive traits of individuals being selected for reproductive success. Also, while changes in population size may indirectly impact genetic drift, they do not define it. Genetics and evolutionary change driven by random chance events like those found in genetic drift are fundamental concepts in population genetics, illustrating how allele frequencies can fluctuate over time, contributing to the evolution of species.