What is genetic drift in the context of population genetics?

Genetic drift refers to the changes in allele frequencies within a population that occur due to random sampling effects. This is particularly significant in small populations, where random events can lead to large fluctuations in allele frequencies from one generation to the next. Unlike natural selection, which involves differential survival and reproduction based on advantageous traits, genetic drift is stochastic in nature.

For instance, if a small population experiences a random event, such as a natural disaster, certain alleles may become more or less common simply because individuals carrying those alleles happen to survive or reproduce by chance. Over time, this can lead to the loss of genetic variation or fixation of certain alleles, irrespective of their effects on fitness. As such, genetic drift plays a crucial role in shaping the genetic structure of populations, particularly those that are small or isolated.