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Tuesday, July 22, 2014

Chinese Adam


A brand new paper (Wu, Crevecoeur, Liu, Xing and Trinkaus, 2014) [1], looks into the shape of the internal ear in ancient humans from China and the fact that the labyrinths in one of the specimens (Xujiayao 15) is quite similar to those of Neanderthals. The paper's objective however is not to prove admixture between Neanderthals and archaic Chinese humans (these remains are 100 ky old!). To the contrary, its purpose is to downplay the similarity and suggest that it is not due to admixture but to shared ancestral Homo features and that "many of the purported 'Neandertal' features were widespread during the Pleistocene, albeit often occurring in higher frequencies among the Neandertals" [1].


I am surprised at the efforts of the authors to separate these Chinese remains from the Neanderthals and to link them to "ancestral " non-Neanderthal archaic humans, this post describes these efforts and tries to explain possible reasons for this unusual position.


The Chinese origin of mankind


Yes, that is what is behind the attempt to de-Neanderthalize the Xujiayao 15 remains: support a Chinese origin of mankind.


Let's quote Xiu-Jie Wu and team: [1]


"Regardless of the ultimate populational and morphofunctional implications of the Xujiayao 15 and the other East Asian labyrinthine configurations, they serve to further confirm the general modern human pattern as the ancestral Homo one and to document that the apparently derived Neandertal configuration was not unique to western Eurasia. Given its presence in Europe, southwest Asia, central Asia, and now eastern Asia, it may well have been present across Eurasia during the later Pleistocene among archaic humans. As such, whether a discrete feature in itself or a secondary consequence of other aspects of morphological variation, it becomes less of a “Neandertal” marker and of broader relevance to the paleobiology of later Pleistocene Homo." [1]


The fact is that the inner ear morphology in Neanderthals is slightly different to that of modern humans. This particular shape is not present in modern humans or among the Pleistocene hominids outside of East Asia. The paper however reports that they detected the Neanderthal inner ear shape in one (1) out of four (4) East Asian crania that they studied: it appeared in the Xujaiyao 15 skull. The chart they include in their paper (see Fig. 2. in [1]) clearly shows the Xujiayao 15 skull grouped together with all the Neanderthal skulls in a neat cluster.


The authors grudgingly admit this link: "Xujiayao 15 [...] falls entirely with the Late Pleistocene Neandertals, distinct from the early and recent modern humans and from the Early and Middle Pleistocene Homo." [1]


It is of course significant because it is "the first documentation of this pattern among Pleistocene Homo outisde the Neanderthal geographical range" [1], that is, outside of the Western Eurasian territory that is well known to have been occupied by Neanderthals, which spanned the continent from Spain and France in the West to Altai, Siberia in the East.


But, as I mentioned above, they downplay this clear evidence of Neanderthal admixture and try to attribute it to other causes:


  • The "External morphology [of the labyrinth] bears little affinity to that of the Neanderthals. It shares ancestral Homo features with the Neanderthals". Of course it does, it is what you would expect because Neanderthals predate modern humans and would have "ancestral features", but as we will see below, the authors use the "ancestral features" with another meaning: Neanderthals and the Xujiayao 15 man share this ancient trait because they both got it from an even older ancestor.
  • They list some anatomical elements that are absent or different but must admit that "these aspects of Xujiayao 15 can be found on individual Neanderthal specimens..."
  • The write that "A couple of [Xujiayao] features are common among the Neanderthals but not unique to them" [1] as if this would make Xujiayao less Neanderthal-like. And then, to support this, they analyse the remains of Other Xujiayao specimens which seem different to Neanderthals, ignoring specimen #15 (which is not mentioned, making me wonder if it differs or is it similar to Neanderthals in these traits?)
  • They mention a specimen from Uzbekistan which was classed by its teeth as a Neanderthal, which also has a similar inner ear morphology but point out that it has "an apparent mix of morphological features in other aspects"[1] which are not Neanderthal. I believe that the reason for bringing up this specimen is that if remains closer to the Neanderthal homeland are not so Neanderthal-like, then why should a Chinese specimen be expected to have admixed with Neanderthals.

They emphasize that "It is tempting to use it [the labyringh morphology] as evidence of population contact (gene flow) between central and western Eurasian Neandertals and these eastern archaic humans", but the Xujiayao 15 is "otherwise distinctly 'non-Neanderthal'" (if one ignores the similar inner ear shape).


The paper concludes that despite this apparent resenmblance, the evidence seems to "suggest that many of the purported “Neandertal” features were widespread during the Pleistocene, albeit often occurring in higher frequencies among the Neandertals." [1]


The paper's efforts to ignore the presence of Neanderthals in East Asia during the period of Xujiayao 15 are indeed surprising. But then, there is a logic behind those efforts.


Admixture and its implications


These are old remains, > 100ky and that means an even older date for admixture and Neanderthal presence in the region. And that goes against the theory favored by many Chinese scholars.


Context on the Xujiayao site. The site where these Chinese remains were found is located in Shanxi Province, on the Liyigou River. The remains were discovered in 1974 and were assigned to archaic Homo sapiens.


They are old because some rhino teeth from the site were dated to 104 - 125 kya using Uranium series, but the relationship between Xujiayao bones and the teeth is still unclear.


This dating places these archaic hominins in China long before modern H. sapiens emerged from Africa (that is, if the OoA theory is correct). They could be the easternmost remains of the first Homo sapiens move out of Africa ~ 120 kya., or the result of even more archaic Asian hominins mixing with other archaic Western Eurasian populations such as Neanderthals...


The point is that Neanderthals as a group are far older than the 104 -125 ky age assigned to Xujiayao people since they date back at least 300 ky. Their older origin gave Neanderthal plenty of tieme to have reached China long ago (say 250 kya) and mixed there with late coming humans or even local hominins descended from Asian H. erectus.


In fact this is what Wu Xinzhi proposed over a decade and a half ago:


Continuity with hybridization


Studies on the cranial morphology which compared European Neanderthals and Chinese crania led Wu Xinzhi (1998, 2004)[2][3] to put forth the "continuity with hybridization" model of human evolution in China. Basically Wu Xinzhi's findings suggested that some features found among Neanderthals are also found in Chinese fossils and that this was due to admixture between Neanderthals and Mid-Late Pleistocene hominids.


Wu Xinzhi imagined that the gene flow came from Europe, now we know that Neanderthals were much closer to China (Altai), which in my opinion supports the admixture theory. [2]


The work of Wu Xinzhi was not cited in the paper by Xiu-Jie Wu and team (2014) [1] and the paper itself is against the notion of admixture despite the fact that recent genetic studies support Neander - East Asian admixture: (Wall et al., 2013) "on average the “Neanderthal haplotypes” were [found] at higher frequency in the East Asians than in the Europeans (9.6% vs. 6.4%)" and "that East Asians (Han Chinese and Japanese) are more similar to the published Neanderthal sequence than are Europeans." [7]., making it likely that there was ample admixture in the Far East.


The reason that Chinese scholars now oppose to admixture with Neanderthals is probably due to some current Sinocentric point of view: how could Neanderthal, a Western Eurasian creature (which for over a century and a half was associated with Europe) have admixed with the ancestor of modern Chinese people?


The theory of a Chinese ethno-genesis of mankind is especially attractive to the Chinese; it was supported by Chinese intellectuals from the early 1920s and later by the Communist regime right through to the 1980s.


Zhong chinese symbol

The symbol above is the first part of the name of China, it is a rectangle struck with a line, it means Center, Middle (Zhong) the second part of the name of China means "country", hence China means "Central country". Chinese are extremely proud of their self percieved uniqueness


Initially the Peking man was proposed as a direct ancestor of Mankind, but with growing support for the Out of Africa theory, the model was later adapted to contemplate interaction and hybridzation between the Peking Man (H. erectus) and other populations, evolving into Homo sapiens in situ, in China, and being the origin of modern Chinese.[4][5]


I believe that Wu Xinzhi's support of a Neanderthal admixture made his paper not suitable for citation in the Xiu-Jie Wu et al. publication [1].


Chinese Adam


Rereading the paper by Xiu-Jie Wu and team I notice not only a reluctance to admit admixture with Neanderthal, but also a lot of emphasis placed on the fact that the alleged Neanderthal trait were actually "present across Eurasia during the later Pleistocene among archaic humans" [1] , in other words it is a local East Asian trait shared with Neanderthals in Western Eurasia.


This ties in neatly with another paper Wu Liu et al., (2010) [6] which includes the following "revealing" phrase in its title: "...modern human emergence in East Asia". This paper has the same point of view as that of Xiu-Jie Wu and team: "...derived aspects of modern human morphology were present in East Asia in the early Late Pleistocene" [6]. It seems that modern humans appeared in East Asia!!


Below I quote from Wu Liu and team's paper [6] which describes a modern like jaw found in an archaic skull in Zhiren Cave, China (bold mine):


"The human remains are securely dated [...] to the initial Late Pleistocene, >100 kya. As such, they are the oldest modern human fossils in East Asia and predate by >60,000 y the oldest previously known modern human remains in the region.
[...]The age and morphology of the Zhiren Cave human remains support a modern human emergence scenario for East Asia involving dispersal with assimilation or populational continuity with gene flow. It also places the Late Pleistocene Asian emergence of modern humans in a pre-Upper Paleolithic context and raises issues concerning the long-term Late Pleistocene coexistence of late archaic and early modern humans across Eurasia.
[...] It is not easily accommodated into any Out-of-Africa with populational replacement scenario.
[...] coexistence of late archaic and early modern humans across portions of Eurasia, and not just between Africa and Eurasia. Those late archaic humans include the Neandertals in western Eurasia until mid-MIS 3. They also encompass MIS 3 archaic humans in central Asia and Siberia and into at least MIS 5 in northern China. This emerging pattern raises the question of what subtle behavioral patterns may have limited genetic exchange between these two morphologically defined groups of human across portions of Eurasia for tens of millennia. [6]


So here is the point, these archaic Chinese hominins over 100,000 years old date back to the MIS 5 period (which began 130 kya), and are therefore older than the Neanderthals which are placed in Western Asia in MIS 3 (from 60 to 24 kya).


This seems to suggest (and I have read about this elsewhere [8]) that Neanderthals originated from East Asian hominins, the "archaic humans" features are not derived from Neanderthal, actually both groups got it from the same source, the Chinese Adam!


This [8] summarizes that theory: "The back migration of H. yunxianensis to western Eurasia, approximately 600,000 ya, is hypothesized to have led to the vicariance of the archaic species clades H. heidelbergensis/neanderthalensis in Europe and H. rhodesiensis/helmei/sapiens in Africa, replacing H. antecessor and H. leakeyi, respectively." [8]. In other words, an Out of China, which must be more appealing to Chinese scientists than an OoA.


Comment


Personally I do not care if modern humans came to be in Africa, Asia, Oceania or America. I am marvelled by the mere fact that humans evolved on our precious planet Earth. However I am surprised at how nationalism influences science (well it has always done that), and manages to twist evidence to conform to certain beliefs.


In any case, and this concerns Patagonian wild men, ogres and giants, it may mean that some ancestral archaic hominin was in Eastern Asia over 150 kya and may have moved on, through Siberia and Beringia into the New World long before modern humans managed to do so. And, when the ancestors of Amerindians reached the New World, it was peopled by these odd people... monsters from which myths are born


Sources


[1] Xiu-Jie Wu, Isabelle Crevecoeur, Wu Liu, Song Xing, and Erik Trinkaus, (2014). Temporal labyrinths of eastern Eurasian Pleistocene humans. PNAS, www.pnas.org/cgi/doi/10.1073/pnas.1410735111. June 09, 2014.
[2] Xinzhi Wu, (2004). On the origin of modern humans in China. Quaternary International Volume 117, Issue 1, 2004, Pages 131–140, DOI: 10.1016/S1040-6182(03)00123-X
[3] Xinzhi Wu, (1998). Origin of modern humans of China viewed from cranio-dental characteristics of late Homo Sapiens in China. Acta Anthropol Sinica 17(4):276-282
[4] Hsiao-pei Yen,(2012). Constructing the Chinese: Paleoanthropology and Anthropology in the Chinese Frontier, 1920-1950. A dissertation presented at Harvard.
[5] Jin ChangZhu, et al., (2009) The Homo sapiens Cave hominin site of Mulan Mountain, Jiangzhou District, Chongzuo, Guangxi with emphasis on its age. Chinese Science Bulletin, 2009, 54(21): ()3848-3856
[6] Wu Liu et al., (2010). Human remains from Zhirendong, South China, and modern human emergence in East Asia, PNAS 19201–19206, doi: 10.1073/pnas.1014386107
[7] Jeffrey D. Wall et al., (2013). Higher Levels of Neanderthal Ancestry in East Asians than in Europeans. Genetics. May 2013; 194(1): 199–209. doi: 10.1534/genetics.112.148213
[8] Dennis A. Etler, LI Tianyuan, (2010). A Multiple Dispersal Hypothesis for Interpreting the Pattern of Hominan Evolution in China. Online.



Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2014 by Austin Whittall © 

1 comment:

  1. http://www.rense.com/general65/edd.htm
    As an example of the OoC (Out of China) theory in the Chinese media...

    ReplyDelete