“…For example, population bottlenecks and genetic drift have been shown to play a major role in shaping MHC diversity of many wild species (Mikko et al, 1999). Natural populations of muskox (Ovibos moschatus), moose (Alces alces), fallow deer (Dama dama), beaver (Castor fiber), Asiatic lion (Panthera leo persica), cotton-top tamarin (Saguinus oedipus) and the cheetah (Acinonyx jubatus), among others, have shown reduced allelic variation or even monomorphism at the MHC loci, indicating that the presence of high genetic diversity is not a universal feature of this genetic system (O'Brien et al, 1987;Yuhki and O'Brien, 1990;Watkins et al, 1991;Ellegren et al, 1993, Mikko et al, 1999. Studying closely related species with different demographic histories (eg, endangered species that have suffered drastic reductions in population size vs populations that have not gone through genetic bottlenecks) may provide insights into the relative importance of selective and stochastic processes shaping the genetic diversity present at the MHC.…”