There is a new article in Science about rishathra. It seems that Neanderthals mixed with anatomically modern humans three separate times, AMH mixed once with Neanderthals, Neanderthals with Denisovans, Denisovans with something very old and also with Melanesians.
There are some implications: since Melanesians have a subset of the Neanderthal alleles carried by other Eurasians (while the Chinese have a superset), the chance that the Melanesians are, at least in part, the product of a an earlier expansion is increased. As a friend said, the posterior is bigger. This friend is apparently a devotee of both Bayes and Sir Mix-a-Lot.
This brings up the perennial question: what was it like? We’ve all read the usual speculation about a human girl (anatomically modern in all the right places) who, while bathing, encounters a Neanderthal dude returning from a successful hunt, with the striated muscles of his bronzed torso exposed for anyone to see. Even if his verbal skills are limited (old version of Foxp2), maybe he’s a good dancer (Puttin’ on the Ritz). One thing leads to another, until at last his near-manhood can no longer be denied. Romantic, kinda.
But sister species can remain interfertile for a surprising long time, often for a couple of million years, sometimes longer. And some of our hominin cousins diverged very far in that time. For example, Homo naledi may not be all that old: we’re looking for a source of some very divergent DNA in Pygmies and Bushmen, and H. naledi is a possibility – but an embarrassing one. I mean, they had a brain the size of a grapefruit. Same with the Flores hobbits. We’re talking Stinking Lizaveta here.