We are conducting a comprehensive analysis of mitochondrial, Y-chromosome, and autosomal DNA variation in human populations from East Europe, the Caucasus and neighboring groups from Iran and Turkey, to address questions concerning the influence of linguistic and geographic barriers on genetic variation in these populations and to further our understanding of the origins of European populations. We are also studying diversity in the oral microbial community in different human groups, with the ultimate goal of identifying microbes that would be suitable for anthropological studies as a “genetic” marker.