These findings suggest that Baltimore and Bullock's orioles evolved migratory ability independently. Such detailed data would also provide molecular clock estimates for determining whether the Baltimore and Bullock's lineages evolved migration at the same time, perhaps in response to similar selection pressures. We are studying the genetic structure this widespread species using both nuclear microsatellite markers and mitochondrial DNA sequences. The project focuses on detailed sampling of several populations from the Mojave Desert to examine gene flow, population structure and effective population sizes on a local scale. Within North America we will compare California populations to populations from Alaska, Washington, Minnesota and Maine to study differentiation across North America.
Initial data show strong differentiation between California and Maine populations.
Finally, we will compare these populations to several samples from Eurasia to determine if there are large breaks between Old World and New World populations. Molecular Phylogenetics and Evolution . Omland, K. E. 1999. Lanyon, S. M. and Omland, K. E. 1999. Lanyon, S. M. and Omland, K. E. 1998.