Dissecting functional components of reproductive isolation among closely related sympatric species of the Anopheles gambiae complex

Explaining how and why reproductive isolation evolves and determining which forms of reproductive isolation have the largest impact on the process of population divergence are major goals in the study of speciation. By studying recent adaptive radiations in incompletely isolated taxa, it is possible to identify barriers involved at early divergence before other confounding barriers emerge after speciation is complete. Sibling species of the Anopheles gambiae complex offer opportunities to provide insights into speciation mechanisms. Here we studied patterns of reproductive isolation among three taxa, An. coluzzii, An. gambiae s.s. and An. arabiensis, to compare its strength at different spatial scales, to dissect the relative contribution of pre- versus post-mating isolation, and to infer the involvement of ecological divergence on hybridization. Because F1 hybrids are viable, fertile, and not uncommon, understanding the dynamics of hybridization in this trio of major malaria vectors ha...