Cytogenetic Evidence for the Specific Distinction of an Alaskan Marmot, Marmota broweri Hall and Gilmore (Mammalia: Sciuridae)

Authors

Robert L. Rausch, Arctic Health Research CenterFollow
Virginia R. Rausch, Arctic Health Research Center

Date of this Version

5-1965

Citation

Chromosoma (May 1965) 16(5): 618-623.

Comments

U. S. government work.

Abstract

Cytogenetic studies based upon somatic cells (bone marrow) have disclosed that the marmot hitherto designated Marmota caligata broweri Hall and Gilmore, occurring in the Brooks Range of Arctic Alaska, differs from M. c. caligata (Eschscholtz) in number of chromosomes (2n=36 as compared with 2n=42 in M. caligata) and in proportions of chromosomal types. Typical karyograms for the two species are presented. It is concluded that the Brooks Range marmot is specifically distinct from M. caligata, the applicable name being Marmota broweri Hall and Gilmore. Also determined were diploid chromosome numbers for two other Nearctic species of marmots, M. flaviventris (Audubon and Bachman), with 42, and M. olympus (Merriam), with 40. It is suggested that M. broweri survived the last (Wisconsin) glaciations in the amphi-Beringian refugium, and that its closest affinities may be with one of the Eurasian species of Marmota.