Selection by parasites on the MHC has been hypothesized to drive speciation. In Poecilia mexicana from the Cueva del Azufre system, we found that while parasites select for MHC diversity, MHC divergence among locally adapted populations is actually much lower than divergence at neutral loci. This suggests that balancing selection on MHC genes maintains similarities among diverging lineages and could therefore counteract the speciation process. Check out the full story in the Journal of Evolutionary Biology.
Evolution in Extreme Environments
Tobler Lab at the University of Missouri—St. Louis
