The genetic basis of reproductive isolation: insights from Drosophila.
Recent studies of the genetics of speciation in Drosophila have focused on two problems: (i) identifying and characterizing the genes that cause reproductive isolation, and (ii) determining the evolutionary forces that drove the divergence of these "speciation genes." Here, I review this work. I conclude that speciation genes correspond to ordinary loci having normal functions within species. These genes fall into several functional classes, although a role in transcriptional regulation could prove particularly common. More important, speciation genes are typically very rapidly evolving, and this divergence is often driven by positive Darwinian selection. Finally, I review recent work in Drosophila pseudoobscura on the possible role of meiotic drive in the evolution of the genes that cause postzygotic isolation.
Orr
H Allen
HA
Department of Biology, University of Rochester, NY 14627, USA. aorr@mail.rochester.edu
D000818:Animals; D005075:Biological Evolution; D004330:Drosophila / Q000235:genetics* / Q000502:physiology*; D012098:Reproduction / Q000235:genetics* / Q000502:physiology*; D012641:Selection, Genetic; D013045:Species Specificity