What does genetic drift refer to?

Genetic drift refers to random changes in allele frequencies within a population. This phenomenon is particularly significant in small populations where chance events can lead to pronounced shifts in gene frequencies from one generation to the next. Unlike natural selection, which is a process that can favor certain alleles based on their contribution to an organism's fitness, genetic drift occurs purely by chance. Events such as natural disasters or random mating can result in some alleles becoming more prevalent while others may diminish or vanish altogether. This randomness can lead to significant evolutionary changes over time, independent of the adaptive value of the alleles involved.

In contrast, intentional genetic manipulation focuses on human-directed changes in an organism's genetic makeup, which is not a factor of chance but rather a deliberate process. Stable gene frequencies are typically characteristic of large populations where genetic drift has minimal impact due to the buffering effect of larger gene pools against random fluctuations. Controlled breeding within species, although it can influence allele frequencies, is a methodical process rather than an accidental occurrence and does not capture the essence of genetic drift.