Distribution of three inferred genetic clusters in the study regions. Slices in the pie diagrams represent Fat-tailed (yellow), Composite (black) and Nordic (red) clusters. The Caucasus area is represented by four regions: South Caucasus (1), North Caucasus (2), Stavropol (3) and the Caspian depression (4). The Asian region is represented by three regions: Kazakhstan and east of the Caspian Sea region (5), the Altai region (6) and the Buryatia region (7). The remaining groups belong to eastern fringe of Europe: the Volga region (8), West Russia (9), Ukraine (10), Southeast Europe (11) Poland (12), Finland (13), Scandinavia (14), Denmark (15) and Iceland and the Faeroe Islands (16).