What is meant by genetic drift?

Genetic drift refers to a mechanism of evolution that involves random changes in allele frequencies within a population. This phenomenon occurs due to chance events that lead to some alleles being passed on to the next generation more frequently than others, regardless of their impact on survival or reproduction.

In small populations, the effects of genetic drift can be particularly pronounced, leading to significant fluctuations in allele frequencies over time. This randomness can result in the loss of genetic variation and even the fixation of certain alleles, which may not necessarily confer any advantage for survival. Genetic drift is distinct from natural selection, where allele frequencies change due to differential survival and reproduction based on advantageous traits.

Understanding genetic drift is crucial in evolutionary biology as it emphasizes the role of random processes in shaping the genetic structure of populations, particularly in the absence of selective pressures.