What does genetic drift refer to?

Genetic drift refers to the random changes in allele frequencies that occur in small populations due to chance events. This randomness can lead to fluctuations in genetic variation over time, regardless of the fitness of the alleles involved. For instance, if a small group of individuals reproduces, the alleles carried by those individuals may not represent the overall genetic makeup of the larger population, leading to a shift in allele frequencies simply by chance.

In contrast to controlled changes, which involve intentional selection processes or breeding strategies (as seen in selective breeding), genetic drift operates without any direction or selection pressure. This random nature makes it particularly impactful in small populations, where the likelihood of certain alleles becoming more common or disappearing altogether can happen quite rapidly compared to larger populations, where the effects of random events tend to average out. Thus, genetic drift is fundamentally about chance and its influence on genetic diversity within small groups.