John Hawkes gives an interesting write-up relating a recent paper of Indian middle to late paleolithic human population evidence with the increasing genetic evidence of unique Denisovan genetics among the indigenous of Australia and SE Asia east of the Wallace line:

Denisovans and the Middle Paleolithic of India

[…] To my mind, there is a singular point that any hypothesis must accommodate: indigenous Australians and Melanesians have substantial Denisovan ancestry, South and Southeast Asians, and peoples of Java, Sumatra and Borneo have at most a trace of Denisovan ancestry (“How widespread is Denisovan ancestry today?”).

We can’t easily explain this pattern without multiple waves of population movement into Southeast Asia. The later wave (or waves) of movement must have happened after the initial spread of people who would colonize Australia and Melanesia. This later wave (or waves) must have made up the vast majority of the ancestry of later Southeast Asians, including today’s hunter-gatherer peoples of mainland Southeast Asia and the peoples of the Andaman Islands. The source of this later wave must have been from some population that had Neandertal ancestors but did not have Denisovan ancestors.

[…]

Evidence is growing that we are descended from groups of anatomically modern humans from Africa that multiply interacted with other early human populations over a period of several tens of millennia. This would mean our modern ancestry is a kind of a network of ancestral populations, with dominant strands from a single population in Africa but with lots of multiply connecting other strands.