Ancient genomes indicate population replacement in Early Neolithic Britain

The roles of migration, admixture and acculturation in the European transition to farming have been debated for over 100 years. Genome-wide ancient DNA studies indicate predominantly Aegean ancestry for continental Neolithic farmers, but also variable admixture with local Mesolithic hunter-gatherers. Neolithic cultures first appear in Britain ca. 4000 BCE, a millennium after they appear in adjacent areas of continental Europe. The pattern and process of this delayed British Neolithic transition remains unclear. We assembled genome-wide data from six Mesolithic and 67 Neolithic individuals found in Britain, dating from 8500-2500 BCE, a dataset that includes 22 newly-reported individuals and genomic data from British Mesolithic hunter-gatherers. Our analyses reveal persistent genetic affinities between Mesolithic British and Western European hunter-gatherers. We find overwhelming support for agriculture being introduced to Britain by incoming continental farmers, with small, geographically-structured levels of hunter-gatherer ancestry. Unlike other European Neolithic populations, we detect no resurgence of hunter-gatherer ancestry at any time during the Neolithic in Britain. Genetic affinities between British and Iberian Neolithic populations suggest that British Neolithic people were mostly descended from Aegean farmers who followed the Mediterranean route of dispersal and likely entered Britain from northwestern mainland Europe. We also demonstrate variation in pigmentation levels coexisted in Europe by ca. 6000 BCE.