This chapter examines the genetic history of Europe during the past 20,000 years, looking especially at postglacial recolonization and at the much-debated issue of the origins of the Neolithic populations of the continent. The authors also discuss the different ways geneticists can approach population history, and comment on the importance of natural selection for genes that determine skin pigmentation and enhance the ability to digest the milk sugar lactose.

via 18 Europe and western Asia: genetics and population history – The Encyclopedia of Global Human Migration – Thomas – Wiley Online Library.