Biochemical differentiation in the Idaho ground squirrel, Spermophilus brunneus (Rodenta: Scuridae)

Authors

Ayesha E. Gill, University of Nevada, Reno
Eric Yensen, Museum of Natural History, Albertson College, Caldwell, Idaho

Abstract

Spermophilus brunneus is restricted to a 90 × 125-km area of west central Idaho, with two distinct (northern and southern) groups of populations within this limited range. Morphological differences in pelage length and coloration, external and cranial measurements, and bacula suggest that these groups are either very distinct subspecies or species. We used starch-gel electrophoresis to estimate the amount of genetic differentiation accompanying these morphological differences by assaying genetic variation at 31 loci in the two geographic groups. Fifteen loci were polymorphic (13 in the northern group, 12 in the southern), and mean heterozygosity (H¯) was high (12.3% northern and 10.8% southern). Nei's genetic distance (0.057) is in the range usually associated with subspecific differences. However, Jaccard's association coefficient (0.893) is about the same as that found between several ground squirrel taxa currently recognized as species. The high levels of heterozygosity suggest that S. brunneus is a neoendemic rather than a paleoendemic species.

Recommended Citation

Gill, Ayesha E. and Yensen, Eric (1992) "Biochemical differentiation in the Idaho ground squirrel, Spermophilus brunneus (Rodenta: Scuridae)," Great Basin Naturalist: Vol. 52: No. 2, Article 7.
Available at: https://scholarsarchive.byu.edu/gbn/vol52/iss2/7