Fig. 1.

Populating Europe. aDNA research shows that present-day Europeans are the result of a mixture of different ancient populations (blue diamonds): (1) West hunter-gatherers who had inhabited Europe since Paleolithic times; (2) Early European farmers, who descended from Near Eastern farmers and entered Europe during the Early Neolithic; and (3) Steppe herders, who arrived in Europe during the Bronze Age. The steppe herders themselves were a mixture of eastern Eurasian hunter-gatherers (Eastern hunter-gatherers) and Near Easterners (orange squares). Additionally, Europeans have ~2 % archaic ancestry from mixture with Neanderthals that arose ~50,000–60,000 ya, probably somewhere in the Near East (purple star). There is also evidence that admixture with Neanderthals occurred again in Europe (purple triangle), as evident from the DNA of a 37,000–42,000-year-old human from Romania. However, this population appears not to have contributed detectably to later humans in Europe. Grey arrows represent the model for populating Europe inferred from modern DNA analysis. aDNA research refined this model by adding several additional layers of information, including multiple migrations and mixtures leading to present-day Europeans (black arrows)