9707496 Zink Robert Zink and Sievert Rohwer of the University of Minnesota and the University of Washington, respectively, will carry out a study of the geographic divergence of mitochondrial DNA from a variety of widespread, Eurasian species of birds. Their goal is to determine whether common patterns of genetic variation and divergence within each species across Eurasia can be documented. Comparisons of DNA sequences within and among populations reveal whether species are genetically homogeneous across their ranges or whether they have responded via natural selection or genetic drift to isolating barriers, such as mountain ranges or glaciers that isolated ancestral populations. Previous studies by these scientists among New World avifaunas have revealed a mixture of population structures, although characteristically, relatively little divergence is observed in regions that were glaciated. Very little is known about this topic in Eurasia, and Zink and Rohwer predict that far more evident patterns will be apparent among Eurasian groups because of less severe impacts of the glaciers. Their comparisons of genetic patterns between North American and Eurasian species will permit an assessment of genetic responses to environmental events common to temperate, recently glaciated continental landscapes. The project also will afford a unique collaboration with scientists from Russia.
