Ancient European genomes, for example, have shown that the populations of Europe at different times in prehistory were radically different from each other and from modern Europeans — that the hunter-gatherers who occupied Europe after the end of the last Ice Age were replaced by incoming farmers from Anatolia, who were later themselves partially replaced by pastoralists from the Pontic steppe, producing the modern European genetic profile from a combination of three major source populations.

This picture — of a European genetic history involving multiple major population replacements rather than simple continuity — was genuinely unexpected, and it required extensive ancient DNA evidence to establish.

Ancient Asian genomes have told an equally complex story — of multiple founding populations, complex patterns of mixture and differentiation, and a deep history of human movement and contact across the world’s largest continent that is still being characterized.

The ancestral populations of South Asia, Southeast Asia, East Asia, and the Pacific show complex relationships to each other and to ancient populations from other parts of the world that reflect tens of thousands of years of movement, contact, and separation.