What is genetic drift?

Genetic drift refers to the random changes in allele frequencies that occur in a population from one generation to the next, primarily due to chance events. This phenomenon is most pronounced in small populations, where random events can significantly alter the genetic makeup without any influence from natural selection or environmental pressures. For example, if a small group of individuals in a population experiences a random event such as a natural disaster, and some alleles are overrepresented or completely lost, the next generation's genetic structure will be different simply due to the randomness of which individuals survived.

This concept is important in understanding how populations evolve over time and how genetic diversity can be affected by chance rather than adaptive traits. It plays a critical role in the evolution of species, influencing not just genetic variation, but also how populations can adapt or become more vulnerable to extinction.