Ancient movement patterns determine modern genetic variances in Europe.

A summary ethnohistory database on population movements in Europe between 2000 B.C. and A.D. 1970 was related to genetic variances and distances based on 26 genetic systems. For the purposes of these analyses, Europe was divided into 85 terrestrial quadrats measuring 5 degrees x 5 degrees. Counts, stratified by time, were taken of the number of movements out of and into each quadrat (called source and target counts, respectively) and between each pair of quadrats. The source and target counts have distinct and different patterns in Europe and vary significantly over time. Central Europe and the Pontic area have the quadrats with the highest source counts, and the Balkans have the highest target counts. Modern genetic variances per quadrat are significantly correlated with source and target counts, somewhat more prominently with source counts. Genetic distances between pairs of quadrats are correlated strongly with geographic distances and moderately and negatively correlated with the total number of movements between these quadrats. Partial correlations of genetic distances with total number of movements, holding geographic distance constant, are small and mostly nonsignificant. These results are interpreted in light of our knowledge of the history and biology of the populations concerned.