Adenosine deaminase polymorphism in the house sparrow, Passer domesticus.

A polymorphism at the adenosine deaminase locus of the house sparrow, Passer domesticus, has been investigated by starch gel electrophoresis. Five alleles have been identified, and most populations seem to be close to the Hardy-Weinberg equilibrium. The allele frequencies differ strikingly across Europe, and in Britian there are significant differences between urban and rural populations. Samples from introduced populations in Australia and New Zealand lack some of the rarer alleles, as predicted from the Founder Effect.