This implies that the Denisovans — or at least populations related to the Denisovans — occupied a large swath of Asia, from Siberia to Southeast Asia and possibly beyond, and that they contributed genetic material to modern human populations through interbreeding at some point during the migration of modern humans through Asia.

A second, geographically distinct population of Denisovans has been identified from the genetic signal in Tibetan and South Asian populations — suggesting that the Denisovans were not a single homogeneous group but a diverse collection of populations spread across the Asian continent, possibly as genetically diverse among themselves as the Neanderthals were across their own range.

The Denisovans were, in other words, a major chapter of human prehistory that had been almost entirely invisible until a single finger bone from a cave in Siberia revealed their existence.

The Meeting Of Two Worlds