Comparative population structuring of molecular and allozyme variation ofDrosophila melanogaster Adhbetween Europe, West Africa and East Africa

Abstract

Summary: Restriction enzyme molecular variation inDrosophila melanogaster Adhwas compared between three natural populations from Europe, West Africa and East Africa. The frequency distribution of silent variation in theslowallele was compatible with the neutral model in all three samples. The number of haplotypes in East Africa was significantly higher than in the other two populations. The largest divergence, as measured byF_st, was between the East African population and a group made up from the West African, the European, and previously studied American populations. We suggest that a split first occurred within African populations at least 44000 years ago. European populations separated from West Africa more recently, between the last glacial maximum and the post-glacial optimum, 18000 to 8000 years ago. We suggest that this species was domesticated recently relative to human evolution, possibly with the advent of agriculture. Population differentiation with respect to the two allozymes,fastandslow, does not follow the geographical pattern of silent variation. It opposes European to both African populations, and probably results from selection for adaptation to alcohol in recent temperate populations.