Hmm .. ye thinking about it, it is kinda strange. Dunno how long you need to roam around until you see some other tribe by chance. But certainly not thousands of years?
it doesn't say that. too few individual remains in too few locations have been found to understand whether the groups had been living near each other for 50,000 years or what their social structures were at all. It would make sense for a species near extinction to have small population clusters migrating and not bumping into each other. They do contrast this with what is known of early modern human genomes in the same areas which do appear to be more mixed, but why wouldn't examples of a newly successful expanding population appear different from remnants of an old population dying out?
so what they found is not at odds with what you are suggesting, but there are other explanations, and not much data
> It would make sense for a species near extinction to have small population clusters migrating and not bumping into each other
What evidence do you suggest supports this for 50k years?
The group Thorin was from may have been close to extinction when he died, but when genetic isolation started they were 50k years away from being that close to extinction. It seems remarkable based on what we know of hunter gathers or even animal population structure and movement, that there would be no mixing for that long.
>What evidence do you suggest supports this for 50k years?
there is no evidence that they were near to each other for 50K years, only that their genomes diverged 50k years ago which was the last time they were near each other.
At the separate-times-and-places that they died in "France", the recent migrants may only have arrived in the last few months, having spent the previous 50K years over in that other far away place, and died only somewhat near each other a decade apart
the mixed genome of early modern humans and the lack of mixing of Neanderthals is a separate piece of evidence, and it may point to Neanderthals not being as sexy-social, but that's just a "may".
But the other contemporary lineages were mixing more than Thorin, and relatedness broadly correlates with geographic proximity [1]. But the contemporary later lineages in the area split off from samples as far as from Siberia and the Caucasus than to Thorin, as this paper demonstrates.
It isn't out of the question that groups could have moved quite a bit since there is evidence of turnover in either Caucasus or Western Europe later on, but I am not sure coming from somewhere else solves the puzzle. Existing evidence suggests that the MRCA of known late Neanderthals including those predating Thorin was in Europe [2].
So Thorin's lineage could have traveled from somewhere without other hominids and beelined for this site ten years prior, but it is not very parsimonious considering he was in a layer with the same PNII style artifacts for thousands of years before and after him? However, the PNII artifacts don't appear to be rooted in the previous ones of the region so perhaps there was an older exotic origin.
We would see the heavy intermixture in one of the groups in that case. In addition, if one group was in homo sapiens captivity, then it is overwhelmingly likely that the other group would be found during those 50 thousand years (considering our propensity for migration).
You don't really need slaves in a hunter and gatherer society (no agriculture, no construction, no mining = no backbreaking work that free people are loath to do), and you don't really have the institutions to keep them from running away.
As far as our observations of Stone Age people go, if they catch someone, they either kill them or make them a permanent member of the group.
Probably enslaved by humans and kept from interbreeding. Alternatively, very strong tribal culture that prevented intermixing like in the tribes in Papua New Guinea.
I don't think slavery made sense for nomadic people. Also, 'slave' is a quite advanced abstract concept for a time when humans could barely speak with eachother.
Relatively high divergence of language across a relatively small geographic area? How often, exactly, are you interacting with people outside your family group? Outside your local group of family groups? Even factoring in nomadism.
Multiple Neanderthal groups in Europe geographically fairly close, on the brink of extinction, yet no interbreeding for 50,000 years.
The stories that pop into my mind!