Variation in Mitochondrial DNA in Populations of Peromyscus eremicus from the Chihuahuan and Sonoran Deserts

Abstract

A 1,439-bp region of the mitochondrial DNA was analyzed for restriction-fragment-length polymorphisms (RFLPs) within and among populations of cactus mice ( Peromyscus eremicus ) from the Chihuahuan and Sonoran deserts. Although five mtDNA haplotypes were detected, none of these was shared between Sonoran and Chihuahuan populations. All analyses of the RFLP variation and concordant morphological, biochemical, and biogeographic data are consistent with the hypothesis that the P. eremicus from the Sonoran and Chihuahuan deserts represent recently diverged species. Pliocene or late Pleistocene pluvial-interpluvial climatic fluctuations are implicated as the primary mechanism in the diversification of the cactus mice from the Sonoran and Chihuahuan deserts.