What effect does genetic drift have on small populations?

Genetic drift has a significant impact on small populations primarily due to its random nature. In small populations, chance events can lead to disproportionately large shifts in allele frequencies. This randomness can result in the loss of alleles, which ultimately reduces genetic diversity.

When certain alleles are lost from the gene pool, the overall genetic variation within the population diminishes. This loss can make the population more vulnerable to environmental changes and reduce its ability to adapt to new challenges. Consequently, reduced genetic diversity can impair survival and reproduction rates over time, affecting the long-term viability of small populations.

In contrast, larger populations tend to buffer against the effects of genetic drift, maintaining a more stable genetic makeup and higher genetic diversity.