What type of effect can small populations have on allele frequencies?

Small populations can significantly influence allele frequencies due to genetic drift, which is the random fluctuation of allele frequencies from one generation to the next. In smaller populations, the effects of chance events are magnified, leading to a higher likelihood that certain alleles may become fixed (reach a frequency of 100%) or lost (reach a frequency of 0%).

This process occurs because with fewer individuals, the chance of any particular allele being passed on decreases, and certain alleles can dominate purely by chance, regardless of their adaptive value. Over time, this can reduce genetic variation within the population since only a limited number of alleles may persist. As a result, in small populations, the effects of genetic drift can lead to notable shifts in allele frequencies that can alter the population's genetic structure.