Testing Simultaneous Divergence of Isolated Avian Populations in the Caucasus

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). This project investigates the ecological and behavioral factors that promote genetic divergence in, and ultimately the evolution of, new species. It focuses on bird species in the isolated forest islands of the Caucasus. DNA sequences from mitochondrial and nuclear genes will be compared for samples of 35 bird species, some of which are non-migratory habitat specialists and others migratory generalists. A new statistical method will be used to test the hypothesis that all populations diverged simultaneously. Because the age of the forests is known, this project will be able to elucidate the time frame involved in the divergence of populations and, for the first time, allow independent calibration of divergence rates of nuclear and mitochondrial genes. Continental islands such as the Caucasian forests are important arenas in which to study evolutionary change because the distance from other populations, time of isolation, and population sizes are standardized. This study will be one of the first tests of the contemporaneous origin of an island fauna. It will reveal whether loss of migration and habitat specialization enhance the effects of isolation and speed the diversification process. Additionally, it will reveal the conservation status of the isolated populations. The results of this study will be of importance to biologists studying speciation and rates of evolutionary change in all types of organisms.