When the draft sequence of the Neandertal genome was analyzed it turned out that there was little difference across non-Africans in their proportion of admixture from this other human lineage. It was a rather strange finding as Neandertals seem to have flourished from Europe to the Altai, and from the ice sheets to the fringes of the Middle East. If Papuans had Neandertal admixture the logical conclusion was that that had to occur in the Middle East. Additionally, if Europeans didn’t have much more Neandertal admixture than Papuans, that means that after the initial absorption the modern humans simply swept the field as they pushed north and west.
But there’s a little problem here: the archeology indicates that Neandertals survived for nearly ten thousand years in Europe after the first arrival of moderns. So the necessary conclusion granting all the above is that after the initial hybridization some barrier prevented further leakage of Neandertal genes into Europeans (or, perhaps modern Europeans descend from recently arrived Middle Eastern farmers who lack the full Neandertal complement of Paleolithic Europeans?).
A new paper in PNAS overturns these paradoxes by re-dating the last Neandertals, allowing them to melt away rather quickly ~40,000 years B.P., just as modern humans were sweeping across Eurasia. Revised age of late Neanderthal occupation and the end of the Middle Paleolithic in the northern Caucasus:
Advances in direct radiocarbon dating of Neanderthal and anatomically modern human (AMH) fossils and the development of archaeostratigraphic chronologies now allow refined regional models for Neanderthal–AMH coexistence. In addition, they allow us to explore the issue of late Neanderthal survival in regions of Western Eurasia located within early routes of AMH expansion such as the Caucasus. Here we report the direct radiocarbon (14C) dating of a late Neanderthal specimen from a Late Middle Paleolithic (LMP) layer in Mezmaiskaya Cave, northern Caucasus. Additionally, we provide a more accurate chronology for the timing of Neanderthal extinction in the region through a robust series of 16 ultrafiltered bone collagen radiocarbon dates from LMP layers and using Bayesian modeling to produce a boundary probability distribution function corresponding to the end of the LMP at Mezmaiskaya. The direct date of the fossil (39,700 ± 1,100 14C BP) is in good agreement with the probability distribution function, indicating at a high level of probability that Neanderthals did not survive at Mezmaiskaya Cave after 39 ka cal BP (“calendrical” age in kiloannum before present, based on IntCal09 calibration curve). This challenges previous claims for late Neanderthal survival in the northern Caucasus. We see striking and largely synchronous chronometric similarities between the Bayesian age modeling for the end of the LMP at Mezmaiskaya and chronometric data from Ortvale Klde for the end of the LMP in the southern Caucasus. Our results confirm the lack of reliably dated Neanderthal fossils younger than ∼40 ka cal BP in any other region of Western Eurasia, including the Caucasus.
Nick Wade gets some quotes from the principals in The New York Times. I found this part amusing though:
Richard Klein, a paleoanthropologist at Stanford University, said Dr. Higham’s re-dating was “compelling” and fit with his own view that “modern humans were technologically and intellectually far superior to the Neanderthals.” This, he said, “would have allowed them to spread very rapidly and to precipitate the extinction of the Neanderthals almost immediately on contact.”
Klein would think so, he edited the paper in PNAS!
Razib Khan’s degrees are in biochemistry and biology. He has blogged about genetics since 2002, previously worked in software development, is an Unz Foundation Junior Fellow and lives in the western US. He loves habaneros.
May 10th, 2011 at 12:56 am
Perhaps AMHs had some help from the “Campanian Ignimbrite super-eruption” (perfect timing) and/or from domesticated dogs, in addition to a much wider exploitation of natural resources. Something surely scared them the previous ~90,000 year.
“If Papuans had Neanderthal admixture the logical conclusion was that that had to occur in the Middle East. ”
That’s stretching it – it could have been any place between Iran and any of the -stans. Much less likely in the Near East, given population numbers.
May 10th, 2011 at 2:04 am
I’m not writing about this until I hear back from the authors, but you can find in Figure 3 of the paper the 15 Neandertal specimens that date younger than 40,000 years ago, not to mention the scores of Mousterian sites dated after that time.
I would have said there is controversy about Neandertals after 30,000 years ago, but not 40,000 — not by a long shot.
May 10th, 2011 at 6:03 am
How the northern Caucasus became “maybe all of Europe” doesn’t sound right, I’ll wait for John Hawks to get back to us.
May 10th, 2011 at 7:43 am
Did they get any of those “ultrafiltered bone collagen radiocarbon dates” for modern humans in Europe? If those dates get pushed back as well, doesn’t the problem come back?
May 10th, 2011 at 8:49 am
It is also worth noting that Neanderthal extinction 30,000 years ago, as opposed to 40,000 years ago does not necessarily imply 10,000 years of co-existence. Estimates of the duration of co-existence in any one place that I’ve seen are on the order of 1,000 years, and the amount of interaction during this slow retreat may have been modest.
May 10th, 2011 at 10:25 am
I find they mixed too many and different things in a non very scientific (even not very ethical, i’ll dare to say) way:
On one hand, we have the empirical scientific result: a new C14 datation of a Neanderthal. It goes with what it lokks like a big metodological innovation (Ultrafiltration incorporated to method).
Then we go into the realistic consecuences of the empirical scientific results. It seems that a huge revision will be necesary now, both of scores of industries (including EUP) and dozens of human bones (Neanderthal and AMH) for OIS3.
And finally we get in what i’ll call narcisists fantasies: I’m talking about those hiperboled final conclusions, wich are completely and artificially narrowed to the absurd, molded to be of relevance for only the OIS3-Neanderthals.
May 10th, 2011 at 10:31 am
Estimates of the duration of co-existence in any one place that I’ve seen are on the order of 1,000 years
But according to this study they only lasted a few hundred years (thus implying fast retreat/extinction). There is a big difference.
May 11th, 2011 at 8:21 am
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May 13th, 2011 at 3:06 am
The other thread took a weird turn, so please let me apologize here – my choice of words wasn’t very wise. At least we know now that some people actually got the humor intended in my user name…
I of course agree with many that one also has to look at the dating of sites that do *not* contain human bones, and some of these seem to be reliably after 40,000 years ago and associated with Neanderthals. The question is, how many of them, where, and at what time? I still believe that the paper raises a good question, in this context. And I find that John Hawks’ comment “But there’s really no serious challenge to the idea that Neandertals existed in Western Europe after 40,000 years ago” is a strawman argument is the sense that the paper in question never really states that. There are subtle but important differences that got lost in translation in the press release and in the media.