Low gene variation in Drosophila busckii.

Study of allozyme variation in D. busckii at thirty loci gives the proportion of polymorphic loci =.166 and the proportion of loci heterozygous per individual =.044. D. busckii has a narrower seasonal and food niche than the other domestic species D. melanogaster which has more allozyme variation. It is suggested that the low gene variation in D. busckii might be due to adaptation of this species to a narrow niche.