Genetics and the population history of Europe

Abstract

Analysis of genetic variation among modern individuals is providing insight into prehistoric events. Comparisons of levels and patterns of genetic diversity with the predictions of models based on archeological evidence suggest that the spread of early farmers from the Levant was probably the main episode in the European population history, but that both older and more recent processes have left recognizable traces in the current gene pool.

Figure 1

A scheme of the main demographic processes documented in the archeological record of Europe. Numbers are approximate dates, in years before the present. Green arrows, Paleolithic colonization; red arrows, Mesolithic reexpansions (glacial refugia are represented by red circles); blue arrows, Neolithic demic diffusion.

Figure 2

A summary of genetic variation in Europe: first principal component. Different shades of gray represent different values of a synthetic variable summarizing allele frequencies at 120 protein loci. (Cavalli-Sforza, L. L., et al., The History and Geography of Human Genes. Copyright © 1994 by PUP. Reprinted by permission of Princeton University Press; ref. .)

Figure 3

Observed frequency of identical sequences in 780 pairwise comparisons of 40 European mitochondrial population samples. The two boxes refer to the range of expected values, estimated assuming two rates r of population growth (r = 0.005 and r = 0.008) and a Paleolithic (40,000 years ago; box A) or a Neolithic (4,000 years ago; box B) separation of the gene pools.