Systematics and biogeography of the Great Basin pocket mouse, Perognathus parvus
The Great Basin pocket mouse, Perognathus parvus, has a distribution that extends across three geological regions: Columbia Plateau, Great Basin and Colorado Plateau. Limited ability of P. parvus to disperse over large areas and across areas of unsuitable habitat provide a foundation for studying biogeographic vicariance hypotheses related to its distribution. Vicariance hypotheses involving late Tertiary geotectonic events and dispersal hypotheses of Pleistocene glacial-interglacial climatic cycles that may be responsible for phylogeographic structure in P. parvus were tested using mitochondrial DNA (mtDNA) sequences and Restriction Fragment Length Polymorphisms (RFLPs). High levels of sequence divergence support the hypothesis of late Tertiary isolation of Columbia Plateau from Great Basin populations of P. parvus due to late Miocene uplift of the Blue Mountains. Other species exhibit distributions similar to P. parvus and may show the same type of phylogeographic disjunction between populations from the Columbia Plateau and populations from the Great Basin.