Biochemical Systematics of Chaetodipine Pocket Mice, Genus Perognathus

Abstract

Relationships of pocket mice of the subgenus Chaetodipus were examined through the use of electromorphic biochemical characters. Twenty-two loci were used for comparisons among all species, and up to 29 loci were used for analyses of infraspecific geographic trends. The traditional taxonomic view of species-group membership is not corroborated by genetic characters. Instead, divergence within the genus appears to have occurred in a consistently asymmetrical fashion with the extant species lineages having developed prior to or during the early part of the Pleistocene. Infraspecific diversification, particularly that involving formation of chromosomal races, however, was largely mid to late Pleistocene in origin. P. hispidus is the most divergent member of the group and P. formosus is clearly a member of the subgenus Chaetodipus rather than an aberrant member of the subgenus Perognathus, where it traditionally has been placed.