The Denisovan fossil and the DNA it contained indicate that early modern humans coexisted in Asia with other archaic hominin species, but, unexpectedly, that they interbred with them. Like Neandertals, Denisovan population intermixed with modern humans as they dispersed into Asia. In fact, there’s evidence that the genetic adaptations to high altitude in present-day Tibetans come from Denisovans. If confirmed, this is a great example of how intermixing with local archaic populations has shaped, and helped, the spread of modern humans around the world. In this case, it allowed humans to colonize the Tibetan Plateau perhaps faster than they would otherwise have been able to.
Baishiya Cave is an extraordinary site that holds tremendous potential to understand human origins in Asia. Future work in Baishiya Cave may give us a truly unique access to Denisovan behavior and solidifies the picture that is emerging, which is that Denisovans, like Neandertals, were not mere offshoots of the human family tree—they were part of a web of now-extinct populations that contributed to the current human gene pool and shaped the evolution of our species in ways that we are only beginning to understand.
Written by Charles Perreault PhD