Question

being born with extra fingers on a hand is called polydactyly. this is more common in some populations in north america than others due to ______. multiple choice an increase in mutation rate in these populations natural selection in favor of extra fingers in these populations a founder effect because their ancestors from europe carried the alleles random mating with other populations in north america migration of people with multiple fingers out of the population

Explanation:

Polydactyly's higher prevalence in specific North American populations is typically due to the founder effect: a small group of European ancestors carrying the allele for polydactyly established these populations, leading to the trait being more common in their descendants. The other options are incorrect: there's no evidence of elevated mutation rates here, natural selection does not favor this non-adaptive trait, random mating would reduce trait concentration, and emigration of affected people would lower prevalence.

Answer:

a founder effect because their ancestors from Europe carried the alleles