Californian sea otter populations likely have an excess of heterozygotes because their populations were heavily harvested in the 1930s until very small in number. A trait that provides a greater level of fitness compared to those lacking it is called an adaptation. In a hypothetical population with two alleles (A and a) where 20 individuals are homozygous for a, 20 homozygous for A, and 60 heterozygous, the frequency of the A allele is 0.50. Genetic drift within a founding population would most likely lead to homogenization of allelic frequencies that differ from the original population.