In which type of population is random genetic drift weakest?

Random genetic drift refers to the changes in allele frequencies in a population that occur by chance, particularly in small populations. This phenomenon is most pronounced when the population size is small because random events can have a larger impact on the genetic structure of a small population. In contrast, in large populations, the sheer number of individuals mitigates the effects of chance events, leading to more stable allele frequencies over time.

In large populations, the large sample size buffers against extreme changes, allowing for a greater representation of alleles and reducing the probability that allele frequencies will change significantly just by random chance. For example, if a random event selectively eliminates a few individuals, in a large population, the overall gene pool remains largely unaltered, whereas in a small population, those same events can lead to significant shifts in genetic diversity and allele frequency.

This understanding illustrates why random genetic drift is weakest in large populations, making them less susceptible to random changes compared to smaller or more isolated populations.