Mutant allele frequencies in the cat population of Omaha, Nebraska.

The phenotypes of 256 cats seen in Omaha, Nebraska, during the summer of 1983 were recorded and compared to those of other midcontinental USA cat populations. When cats that were "pure-bred," or derived from pure breeds, were excluded, random breeding at the O locus was confirmed and mutant allele frequencies were: O = 0.352, a = 0.813, tb = 0.354, d = 0.525, I = 0.369, S = 0.197, and W = 0.039. Siamese and Himalayan cats constituted 10.9 percent of the total sample (cs = 0.342), but analysis suggests that they are not randomly mating with the general population. Mutant allele frequencies of Omaha cats are more similar to those of cats in Champaign, Illinois, than to those of St. Louis, suggesting that an overland route was more important than a river route in founding the Omaha cat population.