Lewontin's Paradox

Lewontin's Paradox refers to the puzzling observation that genetic diversity within most species is surprisingly similar, despite differences in their population sizes. Theory suggests larger populations should have more genetic variation, but in reality, some species with huge populations don’t show much more diversity than smaller ones. Possible explanations include factors like natural selection, genetic bottlenecks, or limits to how much diversity can accumulate, which help explain why genetic variation doesn't scale directly with population size. This paradox highlights gaps in our understanding of evolution and genetic diversity dynamics.