Over this vast span of time, both groups left remains in the cave, suggesting either that they used it alternately (at different seasons or in different periods) or that they occasionally shared it.

The world that Denny inhabited — with Neanderthals occupying the highlands of central Asia, Denisovans occupying what may have been an enormous range across eastern Asia, and modern humans still confined primarily to Africa — was a world of genuine human plurality.

Multiple types of humans, with different evolutionary histories stretching back hundreds of thousands of years, inhabiting overlapping or adjacent territories, living in ways that reflected their different evolutionary paths but that also, apparently, allowed for the social contact that could produce children like Denny.

The Tools In The Cave