What is genetic drift?

Genetic drift refers to random changes in allele frequencies within a population over time, particularly in small populations. This phenomenon occurs due to chance events that cause certain alleles to become more or less common, independent of their adaptive value. For example, if a few individuals with specific alleles happen to survive to reproduce purely by chance, the frequencies of those alleles may increase in the next generation. This can lead to a loss of genetic variation in the population over time.

Genetic drift operates alongside other mechanisms of evolution, like natural selection and mutation, but it stands out due to its random nature. It can have significant effects on small populations where random events can drastically alter allele frequencies compared to larger populations where such events are statistically less impactful. Understanding genetic drift is essential in fields like conservation biology, where managing small populations can prevent loss of genetic diversity.