Abstract
The distribution of kangaroo mice, genus Microdipodops (Rodentia: Heteromyidae ), is limited exclusively to the hydrographic Great Basin region of western North America (Hafner, 1978; 1993).The phylogeography of populations of the Dark Kangaroo Mouse, Microdipodops megacephalus, were examined within this region using mitochondrial DNA (mtDNA) sequence data. Polymerase chain reaction (PCR) was used to amplify the 16S rRNA gene of which we analyzed a 550 bp fragment for 42 individuals from 19 separate localities. Two phylogenetic trees, neighbor-joining distance and strict consensus parsimony, were constructed using these data. Both trees depict patterns of relationship that suggest a strong east-west division within the distribution of M. megacephalus .
