Historical biogeography of Drosophila simulans based on Y-chromosomal sequences.

Y-chromosomal sequences have been used for phylogeographic studies in humans and other mammals, but so far have been ignored as a source of historical information in Drosophila and other insects with X/Y sex determination. Here, we present the first phylogeographic study of Drosophila simulans based on the Y chromosome. Geographic distribution of Y-chromosomal haplotypes suggests a high degree of population subdivision within Africa, as well as between the African and cosmopolitan groups of populations. Consistent with earlier studies based on autosomal and X-linked loci, our results suggest that D. simulans originated in Madagascar or East Africa, and that the South and West African populations of this species are derived.