Genetic drift is most significant in which type of population?

Genetic drift refers to the random fluctuations in allele frequencies that can lead to significant changes within a population, particularly affecting smaller populations. In a small, isolated population, the effects of genetic drift become pronounced because there are fewer individuals to contribute genetic variability. This limited genetic pool means that random events—such as the loss of individuals due to chance—can lead to large shifts in the population's genetic structure.

In small populations, certain alleles may become fixed (reach a frequency of 100%) or lost (reach a frequency of 0%) due to these random sampling effects. Therefore, genetic drift can lead to rapid changes in allele frequencies and greater divergence from other populations. This phenomenon can result in decreased genetic diversity, making the population more vulnerable to environmental changes and diseases, further emphasizing the significance of genetic drift in small, isolated settings.