The origins of continental biotas are much less well-known than are those of islands. This results in large part from the complexity of continental faunas. The PI intends to develop rigorous phylogenies for three widespread and diverse genera of rodents (Perognathus, Chaetodipus and Onychomys), and to infer patterns of migration, speciation, and extinction based on those phylogenies. The primary tools for development of the phylogenies are parsimony analysis based on mtDNA sequences. This will also permit the PI to explore processes of speciation.
