Two highly abundant native species of mice inhabit the forests of Washington and nearby parts of the Pacific Northwest. They appear virtually identical, as small brown-gray mice with long tails, but the Deer Mouse (Peromyscus maniculatus) is found over most of the North American continent, whereas Keen’s Mouse (Peromyscus keeni) lives only within the forests of Washington and the nearby Pacific Coast to southeastern Alaska. Burke researchers have investigated the historical background of the local Keen’s Mouse in comparison to the geographically wide-spread distribution of the Deer Mouse by comparing their DNA sequences. Despite their similar physical appearance, the two species show a strong difference in mitochondrial DNA. Graduate student Xiaoguang Zheng was able to calculate migration rates of the genes over the past 2 million years. The two mice have been maintained together as distinct species, with complex and not well understood ecological interactions, during a series of habitat shifts that have occurred in response to climate changes and glaciers that have come and gone from our area about 20 times during this period.

Investigators:
Xiaoguang Zheng was a Burke Museum graduate student and obtained his Ph.D. in Zoology in December 2003. He has returned to China to develop a research program in molecular ecology and biodiversity at the Kunming Institute of Zoology.
Brian Arbogast was a postdoctoral fellow at the Burke Museum and is now an Assistant Professor at Humboldt State University in California.
Jim Kenagy is Curator of Mammals at the Burke Museum and Professor of Zoology in the Biology Department.

Publication:
X. Zheng, B.S. Arbogast, and G.J. Kenagy. 2003. Historical demography and genetic structure of sister species: deermice (Peromyscus) in the North American temperate rainforest. Molecular Ecology 12:711-724. Technical Summary

Links:
Peromyscus maniculatus
Peromyscus keeni