Another (?)-worthy paper has just appeared in Nature in the heels of the African ancient genome paper. Time will tell how these worldview-altering discoveries will change the story of Mankind, and a degree of skepticism is warranted. In the view I've held for a few years, modern humans expanded to Arabia before 100 thousand years ago, started leaving it 70 thousand years ago as the ecological situation worsened due to desertification and broke through the "Neandertal barrier" between 70-50 thousand years ago when they developed the skills and technology to overcome them.
The new paper claims that modern humans were in China 80 thousand years ago and came to Europe much later because Neandertal represented a barrier to successful entry to Europe. This begs the question of how they reached China without encountering Neandertals, as Neandertals were also in West Asia where -presumably- they passed through to get to China. A coastal route to south China would explain away this problem, but the coastal migration is usually envisioned much later, at around 60 thousand years ago. On top of that, how did Chinese end up having equal (or more) levels of Neandertals admixture if modern humans first went to China and later moved west and successfully outcompeted the Neandertals. How were they able to do so eventually? (There is no evidence that the kind of advantages associated with behavioral modernity first emerged in East Asia). It's possible that there were 80 thousand year-old modern humans in China (just as there were 100 thousand year-old modern humans in Israel), but that the later East Asians are not descended from them.
One would think that science would present an increasingly reasonable and consistent picture of the past, but it seems that we're a very long way from the point where the dust settles and the puzzle pieces start falling into place.
Nature (2015) doi:10.1038/nature15696
The earliest unequivocally modern humans in southern China
Wu Liu, María Martinón-Torres, Yan-jun Cai, Song Xing, Hao-wen Tong, Shu-wen Pei, Mark Jan Sier, Xiao-hong Wu, R. Lawrence Edwards, Hai Cheng, Yi-yuan Li, Xiong-xin Yang, José María Bermúdez de Castro & Xiu-jie Wu
The hominin record from southern Asia for the early Late Pleistocene epoch is scarce. Well-dated and well-preserved fossils older than ~45,000 years that can be unequivocally attributed to Homo sapiens are lacking1, 2, 3, 4. Here we present evidence from the newly excavated Fuyan Cave in Daoxian (southern China). This site has provided 47 human teeth dated to more than 80,000 years old, and with an inferred maximum age of 120,000 years. The morphological and metric assessment of this sample supports its unequivocal assignment to H. sapiens. The Daoxian sample is more derived than any other anatomically modern humans, resembling middle-to-late Late Pleistocene specimens and even contemporary humans. Our study shows that fully modern morphologies were present in southern China 30,000–70,000 years earlier than in the Levant and Europe5, 6, 7. Our data fill a chronological and geographical gap that is relevant for understanding when H. sapiens first appeared in southern Asia. The Daoxian teeth also support the hypothesis that during the same period, southern China was inhabited by more derived populations than central and northern China. This evidence is important for the study of dispersal routes of modern humans. Finally, our results are relevant to exploring the reasons for the relatively late entry of H. sapiens into Europe. Some studies have investigated how the competition with H. sapiens may have caused Neanderthals’ extinction (see ref. 8 and references therein). Notably, although fully modern humans were already present in southern China at least as early as ~80,000 years ago, there is no evidence that they entered Europe before ~45,000 years ago. This could indicate that H. neanderthalensis was indeed an additional ecological barrier for modern humans, who could only enter Europe when the demise of Neanderthals had already started.
Link
19 comments:
Perhaps the same guys who defeated the Neanderthals in the Middle East/Europe later wiped out the first guys who got to China.
Personally, I don't think coastal routes are all that unreasonable.
All the state sponsored Chinese scientists spent timing pouring over data and long time in India, Europe finally got their money's worth.
These are not the first 80 Ka or even 100 Ka old modern humans found in China, African-like technology (including Aterian type points) was also reported in India soon after 100 Ka BP and also, separately, c. 80 Ka BP and surviving the Toba ash layer afterwards. So this is just another piece of evidence piling up in the same direction.
In fact the window for the OoA seems to be since c. 125 Ka BP into Arabia and up to 90 Ka BP further East. Later the aridity of both Arabia and the coastal regions of South Iran and Pakistan would make it much harder, notably considering the big share of NE African genetic diversity that the migrants carried with them (2/7 of mtDNA L3 sublineages, 1.5/2 of Y-DNA CF'DE ones).
The migration into Arabia and Palestine is archaeologically documented since c. 125 Ka BP, although a second flow may have happened c. 90 Ka BP. The flow into India and China seems to be unmistakably documented since c. 100 Ka BP and even more clearly so for 80 Ka BP.
Neanderthals were in West Asia? Indeed but before 70 Ka BP they only seem documented in the Levant (Syria, maybe parts of Palestine). Since c. 70 Ka BP they migrate not only to Central Asia but also to Yemen, what basically cuts off African from Asian H. sapiens subpopulations until the backflow from Asia in the early UP (c. 50 Ka BP). In any case they were not obstructing the coastal migration route via South Arabia (or other possible routes via the then emerged Persian Gulf marshy "oasis", which was probably one of the first major footholds of "sapiens-kind" in Asia, along with Palestine and South Arabia).
I presume that you are familiar with all or most of the above mentioned facts but if you have any doubt, Dienekes, just ask and I'll provide the reference ASAP.
I was coming here just to link you this fabulous discovery!
This is the last nail in the coffin of the "out of Africa" charade. With the last african genome and now this fossil (that will have more than 80k years, as they are below the level of the 80k stalagmites!), the new trend will be the sapiens "into Africa". Haplotype E is coming like the living show of that :)
Chinese scientists don't believe in Out of Africa. When you eliminate that giant assumption then all of the problems with Out of Africa and weird backmigration patterns become things that support most of humanity coming slowly out SE asia.
Dentition supports this as well. Some tooth features have stayed the same in africa, europe and asia for hundreds of thousands of years.
It's just a matter of time before modern human skulls or ancient dna are found in SE asia or china very early on and the whole thing can be thrown out.
From the intro:
"Notably, although fully modern humans were already present in southern China at least as early as ~80,000 years ago, there is no evidence that they entered Europe before ~45,000 years ago. This could indicate that H. neanderthalensis was indeed an additional ecological barrier for modern humans, who could only enter Europe when the demise of Neanderthals had already started."
Abscence of proof is still not proof of abscence.
What if the Aurignac/Gravettian were proto Cro-Magnon, rather than Neander? There's still some enigmatic sites of NW Europe that existed during the Eem-period and the early Weichselian - simulatnious to the (tropical) population of AMH described in this repport.
How sure are they that those are Homo Sapiens' teeth? As opposed to say Red Deer Cave type hominids or a H. florensis type hominid prior to island dwarfism, or whatever Denisovan is? A 40K year gap does not make sense.
This finding also raises questions about the timing of the peopling of India as well as of China. It will be interesting to see what DNA may be found.
batman:
What if the Aurignac/Gravettian were proto Cro-Magnon, rather than Neander?
Aurignacian and Gravettian are Cro-Magnon (European early modern human) cultures and this is the mainstream view.
It is, of course, not impossible that the dating for both the teeth and the molecular clock are correct. We know of at least two ancient East Asian/SE Asian populations that have left genes behind in modern human populations in the region, one even reaching the Amazon. Modern haplotypes may not have been present in either of these ancient populations.
"This begs the question of how they reached China without encountering Neandertals, as Neandertals were also in West Asia where -presumably- they passed through to get to China".
But Neanderthals may not have entered West Asia until around 70,000 years ago, as the climate cooled allowing the cold-adapted Neanderthals to expand their range. As Maju said:
"Neanderthals were in West Asia? Indeed but before 70 Ka BP they only seem documented in the Levant (Syria, maybe parts of Palestine). Since c. 70 Ka BP they migrate not only to Central Asia but also to Yemen".
Neanderthals even appear to replace Modern humans in the Levant just a little before 70,000 years ago.
"In any case they were not obstructing the coastal migration route via South Arabia (or other possible routes via the then emerged Persian Gulf marshy 'oasis', which was probably one of the first major footholds of "sapiens-kind" in Asia"
Nor were they blocking any possible northern route.
"A coastal route to south China would explain away this problem, but the coastal migration is usually envisioned much later, at around 60 thousand years ago".
And quite possibly in the other direction if the phylogeny of Y-DNA K and mt-DNA hold up.
"In the view I've held for a few years, modern humans expanded to Arabia before 100 thousand years ago, started leaving it 70 thousand years ago as the ecological situation worsened due to desertification and broke through the 'Neandertal barrier' between 70-50 thousand years ago"
Central Asia especially may have been inhabited by Denisovans, thus explaining the surviving Denisovan element in SE Asia.
"One would think that science would present an increasingly reasonable and consistent picture of the past, but it seems that we're a very long way from the point where the dust settles and the puzzle pieces start falling into place".
The only possible conclusion is that the process was far more complicated than usually imagined, with groups moving backwards and forwards in all directions ever since Home erectus emerged.
Since there's never been any sinodonty in africa and it seems to have roots going back 750k years in china, out of asia has much more evidence than any other 'out of' scenario, though I don't think we came out of anywhere, we developed all around the world slowly over time. You know, evolution.
There was no wall of Neanderthals preventing modern human migration in any direction. Neanderthal population densities were always extremely low and isolated. Modern humans could have travelled in a relatively short time across southern Asia without even seeing a Neanderthal. The ability to travel was mainly limited by survival issues -- the ability to obtain food and materials in changing environments. If there was a location where groups would have come in conflict over limited resources, it's just as likely it would have been humans versus humans -- there were simply not enough Neanderthals to make a difference.
When you have to worry about getting food, shelter and proper materials for hunting and gathering, there's really very little time to waste fighting Neanderthals. The "disappearance" of Neanderthals probably had more to do with low reproductive rates which are risky enough in themselves.
The us versus them scenarios involving Neanderthal being obstructions is a rather silly way to reconstruct the course of human migration.
Taking into account the bidirectional point technology at 'Ain Difla in Jordan (which I have argued derives from NE Africa/Arabia, not Levantine Mousterian), we could potentially place the exit from Arabia earlier than 70 ka. The dating of 'Ain Difla is all over the place between 200 - 100 ka, but let's say conservatively it's as recent as 100 ka, this might suggest Nubian Complex toolmakers had expanded as far north as the Levant by this time. While they don't seem to have moved west across the Rift Valley into Neanderthal territory until after 60 ka, we do see bidirectional Levallois point technology (which I argue is Nubian-derived) as far away as the That Desert in Rajasthan and to Kara-Bom and Denisova by 80 - 70 ka. That's not to say bidirectional Levallois point technology is the defining cultural marker for AMH expansion, or even that technology directly correlates with biology, but the distribution of this technology does seem parsimonious with both genetic and skeletal evidence found to date.
In other words, we have not yet found the boundary conditions in which the distribution of Nubian Levallois technology does not correlate with early AMH remains between 125 - 100 ka.
"I don't think we came out of anywhere, we developed all around the world slowly over time. You know, evolution".
Sums it up accurately in my view, a sort of modified 'regional continuity'. However I think everyone accepts that humans' ultimate origin is in Africa, in the form of something like Homo erectus or H. habilis. But also I do think the majority of modern human genetics also has its origin in Africa. But between the two 'out of Africas' there may have been several 'into Africas' as well.
@Unknown: peoples (tribes or whatever) have territories that they exploit economically and consider their own "ideologically". They would normally not allow other peoples settling in them unless forced to.
So the "wall" of Neanderthals is not a "wall", of course not, but rather a reality of peoples (Neanderthals) occupying and claiming certain territories as their own and being for a long time a serious challenge for H. sapiens in combat (definitely much stronger, faster in short runs, good climbers and surely as smart as ourselves). In comparison H. sapiens advantages were longer legs (Marathon runners, long distance trekkers) and a much lighter frame. In the literature we can see how, for the same climatic area, H. sapiens always exploits larger areas than Neanderthals, mobility was on our side but mobility initially brought us to further Asia, where climate was also more in agreement with our basic tropical adaptation.
At some point (initial UP), but not before, it seems that some H. sapiens were in conditions to posit a greater challenge, maybe because of development of ranged weapons (definitely a great advantage in combat vs. Neanderthals) or the domestication of dogs or whatever other reason. Other cultural adaptations included technology to withstand the cold (needle, what means quality clothes), which maybe was also associated to biological adaptations like lighter skin shades (useful for vitamin D metabolism in darker latitudes, what is crucial for several health reasons but particularly for proper brain development in kids). The expansion into the Western Neanderlands was roughly coincident with a northwards expansion in the Far East too, what underlines the newly acquired ability to defy colder climates but also probably the demographic pressures in core Asia (South and SE Asia in essence) pushing people to search for new, more challenging, habitats.
You say that Neanderthals had low densities, however my impression is that they were also expanding, probably for their own internal pressure reasons, especially since c. 70 Ka BP, when we begin finding them in Siberia but also in Yemen (previously a H. sapiens area). Their densities were probably adequate for the niches they occupied relative to Middle Paleolithic "mode 3" technology, shared with our species in the basics. Only with "superior technology" our species seems to have been able or willing to challenge them in their own territory. I don't want to exaggerate technological differences but there must have been some edge of this sort, particularly with ranged weaponry (atlatls probably) which allowed the weaker H. sapiens to fight against the stronger Neanderthals with good chances. There's even one instance of mortal injury in Shanidar (Iran) that has been scientifically argued that must be from an atlatl propelled dart. The date is uncertain but there is no evidence of Neanderthal bone deformations indicating throwing, so it was probably caused by combat with Sapiens (who do show them, at least in Gravettian).
"At some point (initial UP), but not before, it seems that some H. sapiens were in conditions to posit a greater challenge, maybe because of development of ranged weapons (definitely a great advantage in combat vs. Neanderthals) or the domestication of dogs or whatever other reason."
There is evidence of early projectiles by 279,000 BC in Ethiopia (light weight throwing spears but not yet necessarily bows, which appear at Sibudu, S. Africa around 70,000 BC). The species responsible would likely be some form of African "heidelbergensis"-early sapiens- (transitional group). There seems no evidence either way re: the use of spear launching tools (atlatl/woomera) for the Javelins
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0078092
Grogard, this is a science, not a religion, sociology and another irrational thinks. If a Chinese Scientist still don't agree with a Out Of Africa migration with a silly evidence, ignore them because we don't need a subjective opinion. Let the times and a progress of Human technology to shows and proved a solid and logical explanations.
Terryt - I remember when humans were 2 million years old. Now suddenly they are 150k years old. So far I have seen bubkiss to support such an idea, especially because things like tool use are what we were looking at before when we made these judgements.
The more we learn about human origins the more it looks as though we have been a continually changing species from at least two million years ago. Evolution in general has been recently described as resembling a braided river, with branches separating and meeting, mixing and separating once more. Such a process easily explains the presence of both Neanderthal and Denisovan DNA in the modern human species. Presumably contributions from other 'pre-modern' populations will eventually be found. All this makes defining any sort of 'boundary' between pre-modern and modern humans a very mobile target.
Post a Comment