Nature has a new paper, Placing late Neanderthals in a climatic context:
...This study shows that the three sets translate to different scenarios on the role of climate in Neanderthal extinction. The first two correspond to intervals of general climatic instability between stadials and interstadials that characterized most of the Middle Pleniglacial and are not coeval with Heinrich Events. In contrast, if accepted, the youngest date indicates that late Neanderthals may have persisted up to the onset of a major environmental shift, which included an expansion in global ice volume and an increased latitudinal temperature gradient....
The report in Nature News really unpacks the thrust of this paper:
The researchers report in Nature, that of the three main radiocarbon dates given as possible extinction times for the Neanderthals -- 32,000 years, 28,000 years and 24,000 years -- only the most recent seems to have occurred at the same time as a climate shift. This most recent date is also the most controversial, meaning that it is generally more likely that it was competition with modern humans, rather than the bitter cold, that did for the Neanderthals."The take-home message is that we can eliminate catastrophic climate change as a factor for Neanderthal extinction," Tzedakis says.
What to think? I don't know much about stratigraphy and radiometric dating, but, I think context is important. The research on ground sloths in the West Indies strongly suggests that the necessary condition for megafaunal extinction within the last 100,000 years has been the arrival of modern humans. This does not mean it is a sufficient condition, rather, it seems likely that humans force extinctions at the margins. Populations naturally go through cycles dictated by exogenous factors; e.g., climate and disease. It is on the downswings that human predation can send the population over the edge and toward extinction.
In terms of Neandertals, we need to view our cousins as another megafaunal population. They persisted across their extant range for hundreds of thousands of years, shifting north and south with the waxing and waning of the Ice Ages. If climate fluctuations can be thought of as independent trials it stands to reason that many species will naturally experience a sharp enough population crash during one transition that will result in extinction, given enough trials. But, the conditional probabilities of this are altered by the coincidental arrival of modern human beings. And these probabilities need to be modified further by the prior knowledge that modern human arrival seemed to have mysteriously coincided with megafaunal extinctions elsewhere (e.g., Australia and the New World, and also in Madagascar and New Zealand).
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Regarding the 24K date, if Neanderthals were moving South at the onset of each Ice Age, then expanding North again later - mightn't Modern Man living in the Near East and surrounding areas, have blocked Neanderthals natural migration pattern, and hastened their decline, by forcing their number down below replacement levels??
mightn't Modern Man living in the Near East and surrounding areas, have blocked Neanderthals natural migration pattern, and hastened their decline, by forcing their number down below replacement levels??
sounds plausible. i recall that in the near east the two groups had for a while traded off residence depending on the climate. anatomical moderns moved south as neanders retreated from the north. that changed 50,000 years ago as man became behaviorally modern.
I have occasionally wondered if the key to the success of modern humans had to do with out great fecundity, both in terms of our technology and in terms of making babies. The neanderthals were around for at least 100 thousand years yet their popluation never seemed to expand outside of Northern Europe, Spain and the Middle East. In the 50-60 thousand years that modern humans have been around, we've managed to populate almost the entire planet. Was our technology that superior to other human popluations that lived 30 or 40 thousnad years ago? Was it the combination of technology and the ability to have lots of kids? Or was it the way we were organized socially that gave us a competetive edge? Or maybe it was our ability to eat anything. From what I understand, neanderthals were rather meat biased.
The neanderthals were around for at least 100 thousand years yet their popluation never seemed to expand outside of Northern Europe, Spain and the Middle East.
they went pretty far into central asia. see here.
Was our technology that superior to other human popluations that lived 30 or 40 thousnad years ago? Was it the combination of technology and the ability to have lots of kids?
well, the fact that we reproduced fast and spread has to, by definition, but the issue. but yeah, from what i know the tech has gotten better faster since 50,000 years BP. the rate of rate of increase was smaller at first, but has consistently increased (i.e., the third derivation of technology levels is positive).
Where are the living Neandertals?
OK, I realize that I'm probably the most cognitively impaired regular reader of gnxp, but what ever happened to the living Neanderthals?
"You'll never guess..."
Hell, I would love to know just what living (population) group Gregory Cochran was talking about...
It seems obvious from their latitudinally bounded geographic range and everything else known about them - neanderthals were more highly specialised and less adaptable than modern humans. They might also have been not as good at taking care of the women and kids - the women went hunting dangerous big game with the men, so their populations were always pretty small. They may not have had a choice, they might have needed the women along to make up the necessary numbers to hunt successfully, but that had to reduce the reproductive potential of the women and the survival chances of the kids. They didn't grow up any faster than moderns.
So - small populations, not adaptable, pressure from incoming moderns or at least preventing them from moving, and some short term climate fluctuations affecting availability of prey species. That's probably enough.
Susan,
As Razib pointed out, the neanderthal did penetrate into Central Azia. As a matter of fact, it's more than likely the animal got even further into the land mass than we've so far discovered. As the old saying goes, "The range of any extinct animal almost exactly corresponds to the movements of the last dig to discover specimens of it."
Central and Northern Asia are sparsely settled, and very much Terra Incognita. The Russain Far East itself is larger than the continental United States. With a populatin of around 15 million (20% of whom are illegal Chinese immigants). We're talking about millions of square miles tat have not been studied to any great depth.
This means it is very possible there are more neanderthal sites to be discovered. And likely will be discovered as time goes by.
there have been claims (in press) of neandertals in central china.
Razib,
Were you responding to Trout's question? I.e., was Cochran saying that the alleged living Neanderthals are based in Central China?
I've been waiting for some update on this as well.
The meat eating Drung Chang people could be a candidate to Neanderthals. May be.