But both types of evidence have limitations that ancient DNA does not share. Physical remains can tell you a great deal about what a group of people looked like and how they lived. They cannot tell you, with the same directness, who was related to whom, whether populations were mixing or staying separate, where people came from or where their descendants went. Material culture can tell you what people made. It cannot tell you who made it—whether a new tool tradition reflects the arrival of a new population, the adoption of an innovation by an existing population, or a change in social circumstances.
Ancient DNA addresses these questions directly. Population relationships become legible through genome comparisons. Migration becomes detectable through the appearance of ancestry patterns that differ from the local population. Admixture—gene flow between groups—becomes measurable through the presence of ancestry components from multiple source populations. The biological relationships between individuals at the same site become traceable through shared genomic segments.
The implications for understanding prehistory have been substantial. Ancient genomics has repeatedly revised models that were built on physical and material evidence alone. The initial finding that Neanderthals interbred with modern humans was unexpected by many researchers who had interpreted the physical and tool evidence as suggesting replacement rather than integration. The Denisovan discovery was entirely unexpected. The complexity of modern human population structure—with multiple ancient population branches contributing to present-day populations—was not fully anticipated.
Denisova 11 exemplifies what the field can do at its most precise: not just establish that two populations interbred, but document the life of a specific individual who was the product of such interbreeding. This precision is qualitatively different from the precision of population-level inference. Population-level inference tells you that something happened. An individual genome tells you that it happened here, in this person, in this specific biological way.