David Reich: 90% of Ancient Humans Vanished. We Reconstructed Their History.

Ancient DNA analysis fundamentally rewrites human history by revealing complex migration patterns and the existence of "ghost populations" that vanished without archaeological traces. Advancements in sequencing technology now allow researchers to extract and analyze fragmented DNA from mineralized remains, uncovering dramatic population turnovers like the near-total replacement of inhabitants in Great Britain 4,000 years ago. Humans exhibit surprising genetic homogeneity, with most non-African populations descending from a tiny founding tribe 70,000 years ago. Beyond mapping migrations, this research provides a powerful tool for identifying health risks in endogamous groups, such as Ashkenazi Jews, by pinpointing lethal mutations stemming from historical founder events. These genetic insights challenge traditional concepts of identity, nationalism, and racial categorization, offering a scientifically rigorous framework to understand the interconnected, often violent, evolution of our species.