Define genetic drift.

Genetic drift is defined as a change in allele frequencies within a population that occurs due to random sampling effects. This phenomenon can significantly impact smaller populations, where chance events can lead to substantial shifts in genetic makeup over time. For instance, if a few individuals with a particular allele happen to contribute to the next generation more than others, this can lead to a greater prevalence of that allele, regardless of its adaptive value.

This random process contrasts with mechanisms such as natural selection, where the changes in allele frequencies are influenced by the reproductive success related to traits that confer advantages in a specific environment. Genetic drift can result in the loss of genetic variation and can lead to the fixation or loss of alleles simply by chance, making it an important concept in understanding evolution and population genetics.