SYSTEMATIC AND TAXONOMIC IMPLICATIONS OF KARYOTYPIC, ELECTROPHORETIC, AND MITOCHONDRIAL-DNA VARIATION IN PEROMYSCUS FROM THE PACIFIC-NORTHWEST

Chromosomes, allozymes, and mitochondrial DNA (mtDNA) were analyzed to examine the taxonomic and systematic relationships of coastal Peromyscus from northern Washington to southern Alaska. All three datasets indicate that Peromyscus from this region constitute two distinct groups. One group comprises P. oreas, P. sitkensis, and several currently recognized subspecies of P. maniculatus including P. m. algidus, P. m. hylaeus, P. m. keeni, P. m. macrorhinus, and P. m. prevostensis. The second group comprises only populations of P. m. austerus. The former group is differentiated from the latter by number of autosomal arms, allele-frequency differences, and mtDNA haplotypes. This dichotomy in karyotype, and the level of allozymic and mtDNA divergence between the groups suggest that the groups constitute distinct species. We recommend that P. oreas, P. sitkensis, P. maniculatus algidus, P. m. hylaeus, P. m. keeni, P. m. macrorhinus, and P. m. prevostensis be recognized under the specific epithet of Peromyscus keeni.