Monthly Archives: September 2011

The Neolithic colonization of the Valencian Country

The excellent blog in Spanish Language Neolítico de la Península Ibérica discusses today the following paper (freely accesible and in English language):
The paper is indeed interesting even if I am not sure how good the Valencian case is as example, because this area is rather exceptional in the intensity of the apparent colonization. In any case it is very informative for the particulars of this area. 

Briefly: they describe three phases:

  1. Pre-cardial (impressed pottery or “sillon d’impresion”, similar to that of Côte d’Azur) pioneering sites in the 55th century BCE (C14 calibrated).
  2. Cardial phase: increase in density through the area of the southern Valencian Country in the 54th and 53rd centuries; change to Cardium style, possibly related to that of Provence and Languedoc and to the local Macroschematic rock art.
  3. Further expansion both in density and towards the interior (Murcia and Albacete provinces) along the Segura river in the late 6th millennium BCE.

Modified from fig. 6 (superimposing as red dots fig. 4): phases 1 and 2

Comparison between pottery (Cardial) and rock (Macroschematic) art
The authors argue that the process of settlement by the first farming groups in these areas was not as rapid as it was thought, nor as constant as researchers had previously proposed.
If the authors of the paper make a critical read of Zilhao’s fast colonization hypothesis, the always sharp authors of Neolítico en la Península Ibérica make also a critical read of the paper’s colonizationist conclusions which they consider preconceptions, deja vú and a mere repetition of the ‘official hypothesis’ of the ‘Valencian school’. Their main criticisms are that it fails to account for the destiny of the dense pre-existent Epipaleolithic colonization of the area, that it relies too much only on pottery styles, and that the ‘theory’ is a case of the cart before the horses, lacking data that could support the colonization model. 

Phase 3: expansion to the rich interior’s vegas
Said that, I do think that the Southern Valencian Country was one of the areas of the Iberian Peninsula most strongly affected by Neolithic colonization as Y-DNA and other scattered data do suggest. Y-DNA could support a maximum 50% Y-DNA input from beyond the Mediterranean Sea and autosomal DNA might suggest 15% maybe (the Spanish sample in Bauchet 2007 is Valencian and shows variable East Mediterranean admixture ranging from nearly zero to 40%). While not all the Transmediterranean genetic input needs to be of Neolithic age, this one offers an ideal window for a ‘settler founder effect’, though not a replacement, as proposed by some.

______________________ . ______________________
Appendix: graphs on Iberian genetics:


Y-DNA of Iberia per Adams 2008
G, J, K*, E, and maybe even some I could be of Neolithic arrival
Autsomal DNA structure at K=5 (Bauchet 2007, fig. 4)

The red component may indicate Neolithic input from the Aegean

Spanish are from Valencia


Echoes from the past (Sep 24)

And all the rest of the cool stuff in short headlines:

Archaeology and hominin evolution:
Robust australopithecines were indeed relatives, shows CT scan ··> SD.
Neanderthals also exploited seafood resources, as early as H. sapiens ··> El Neandertal tonto ¡qué timo![es].
Looters and bureaucracy destroy a Solutrean site in Andalusia (Higueral-Guardia cave). Sadly enough, it was a lot easier for looters to access the unprotected cave illegally than for archaeologists to do so legally ··> Pileta de Prehistoria[es].
What more classical troglodyte imagery than skulls on sticks? Sadly archaeology had never produced such artifacts… until now: Epipaleolithic Swedes had them ··> Pileta de Prehistoria[en].

Fascinating ‘Nazca lines’ found in Arabia ··> Live Science.

More Neolithic remains from Yesilova (Izmir, Turkey) ··>  Daily News.
Remember the first pampooty shoe (or abarka) found in Areni 1 cave (Armenia)? It has now also produced a skirt ··>
Bronze Age’s stone anchors from the Black Sea ··> Novinite.

Fscinating 3D reconstructions of Stonehenge, Woodhenge, etc. ··> The Heritage Journal.

Stanton Drew reconstruction
Cahokia Mounds researched in some depth finally ··>  BND.
Clay disks from Alaska ··> Art Daily.
A. thaliana
Bronze Age haploid DNA from North China yields no surprises (mtDNA: D4, D*, M7c, A4, F1b, G1a, M9a, M10 and M8z; Y-DNA: N1c and O3) ··> Dienekes.
First Aboriginal Australian genome sequenced ··> Dienekes.
Epigenetic evolution: Arabidopsis thaliana does it all the time, what about humans? ··> SD.
Other sciences:
Quite impressive stuff these days:
Speed of light may not be the ultimate speed limit: neutrinos found going faster. It also challenges the unidirectionality of time ··> Al Jazeera, BBC.
LHC, where the barriers of science are broken
Dark matter challenged by dwarf galaxies ··> BBC.

Dwarf galaxy getting cocky

Special thanks to Stone Pages’ Archaeo News section.


‘Denisovan’ admixture widespread beyond Wallace Line, non-existant elsewhere

Reconstructed H. erectus
Remember that last Christmas we got an unusual gift of knowledge in the finding by Reich et al. that Melanesians of all modern humans researched back in the day were the only ones to show admixture with the mysterious Denisova fingers?
Remember that I said already back then that this admixture was not with Denisovans as such but a related species (probably H. erectus) of which the Denisova hominings were just the tip of the iceberg and a Neanderthal-admixed tip actually.
I proposed therefore that the admixture shown by Melanesians but not continental Eurasians was probably the product of admixture with H. erectus solensis (or something like that) in Indonesia, while ‘Denisovans’ were hybrids of H. erectus and H. neanderthalensis, possibly at near 50% levels.
I suggested then this scenario:

With the 2nd admixture representing this regional H. erectus introgression and the 1st one being that from Neanderthals or maybe a related Heidelbergensis-derived population in South Asia (Hathnora hominin).
I also said that the figures of ‘Denisovan’ admixture had to be cut by half because the authors were counting Neanderthal admixture twice in Melanesians (as ‘Denisovans’ were probably Neanderthal-Erectus hybrids). Quoting myself:

They suggest (supp. info 8) that Melanesians would have as much as 7.4% of admixture with archaic species: 4.8% Denisovan plus 2.5% Neanderthal. But, if Denisovans are hybrids of H. erectus and H. neanderthalensis (as seems most likely, see above), then the real admixture with H. erectus would be an undetermined percentage but always less than 4.8%. As we know that the Neanderthal (or Heidelbergensis) component is 2.5%, it is most likely that the actual Erectus admixture in Melanesians is of only 2.3% or 2.4%, totaling 4.8%.

Now we are told that all the aboriginal peoples of Near Oceania, plus Wallacea and Filipino Negritos, show that admixture at similar or lower levels:
I could browse the paper a day or so ago, so I hoped this was an open access paper. Yet today I find it is PPV. Luckily Dienekes has published most of the relevant graphs at his blog.
In any case the relevant information is this map (from Neanderfollia[cat]):

It tells us that Papuans and Australian Aborigines share the greatest fraction of ‘Denisovan’ introgression, followed by Boungaville Melanesians, Fijians, Timorese, Alorese and Mamanwa speakers (probable Ati). These and other peoples of beyond what used to be the continental landmass of Asia in the Ice Age, retain some level of ‘Denisovan’ admixture. 
But Denisova is very far away and no admixture is known elsewhere. Why? Because the admixture surely happened in or near Indonesia and was not with the Neanderhal-hybridized Denisovans but with pure H. erectus from the region.
Papuans and Australian aborigines have probably 2.4% admixture from H. erectus, in people like the Timorese that would be 1.2% and in a group like the Roti (RO) it is of just 0.6%. That’s my interpretation of the available data. 

But from Sundaland to the West and North there is no such admixture: zero!
And that can only be explained if the admixture happened in Indonesia, maybe in Flores?

Mysterious ‘East Asian’ mtDNA in early European farmers

Linear Pottery from Hungary
This was going to go into a general compilation post but it has already stirred some debate in an unrelated entry, so I thought I’d open a proper space for debate here.
The issue is that a new research paper (Z. Gubba et al., Science 2011, pay per view) has found that many of the mtDNA HVS-I sequences at Hungarian Neolithic sites appear to be what we would usually call East Asian haplogroups, namely N9a (3/11, each from a different site), C5 (1/11), D1/G1a1 (1/11). In addition there are two mysteries: M*/R24 (1/11), maybe related to South Asia, and a novel R* lineage (1/11). Finally there are some more familiar cases N1a (1/1) and R-CRS, interpreted as H (3/11). See this chart provided by Waggg for the details.
The method of testing only HVS-I  has many limitations and one would have hoped that it would not be used anymore. If you are going to damage a valuable archaeological bone, you’d better produce valuable, solid, results and HVS-I does not serve that purpose. But the ego of researchers is infinite, or at lest bigger than my patience. 
Still the N9a lineages seem quite solid. While the 16261 site seems hypervariable (and hence suspicious) 16257 only shows mutation at the root of N9a in all the mtDNA phylogenetic tree as we know it. Its presence along other “Asian” lineages seems to reinforce the consistency of this finding.
However it is still most surprising. Even if C and D do exist in modern Europe (at low levels and mostly towards the NE, ref. – h/t to Waggg again), they have always been thought as rather late arrivals related to Uralic expansion probably. As far as I know N9a has never been reported (certainly not at any meaningful levels) in Europe before now. Not in Neolithic peoples either. 
So it’s the kind of thing that makes you raise both eyebrows and drowns you in doubts. Feel free to debate in the comments section.

Are Hmong-Mien ‘descendant’ from Austroasiatic peoples?

This paper has been for more than a week in my “to do” folder and I really think it deserves a separate mention even if it also leaves me a bit cold:
The authors think that they can track overall Y-DNA flow between Austroasiatic and Hmong-Mien speakers in SE Asia and they therefore believe that, genetically speaking, Austroasiatic peoples are “ancestral” to Hmong-Mien. 
It does not contradict anything I generally espouse for the demographical history of the region, rather the opposite but still it leaves me quite cold. Why? Because the analysis is based on STR rather than SNP-defined phylogeny, what has led to errors in the past, because the authors insist in associating genetics with language and want to somehow argue that Hmong-Mien and Austroasiatic are related just because the speakers are related. That may well be like comparing Jamaicans and Angolans and deciding that way that English and Portuguese are related… and be right by mere chance. Or be wrong or…
Still the supplementary material offers a nice resource for those interested in the detail of East Asian Y-DNA genetics. 
There is also some more detailed information on Y-DNA O, always interesting. For example:

Left to right: O2a1 (M95), O3a2b (M7) and O3a2c1a (M117)

This is the kind of stuff where you really get the impression of how haplogroups are distributed and why it is likely that they coalesced in the South. But we’d need a more complete work of this kind, addressing all major haplogroups.
So, well, there it is and I’m sure that many readers would be interested in knowing about it. But nothing that shakes the world in any case.

Posted by on September 24, 2011 in East Asia, population genetics, SE Asia, Y-DNA


Claims of Nigerian late "archaic" human… highly dubious

That’s the least I can say after looking at the matter with some attention: that the claims made by a recent paper are not sufficiently justified to say the least.
They tell us of a recent pair of skulls from SW Nigeria. They were discovered in 1965 and at least one of them belongs to a whole skeleton, including a critical piece: the mandible. Sadly this paper totally ignores anything but the calvaria (the top of the skull). They have been dated by uranium series to c. 12-6 Ka ago.
Sloppiness seems too common in this paper: not just the two skulls and skeletons are not properly shown in full but, in fig. 1, they claim to be showing both calvaria, they only show one from four angles:

Fig. 1

Then we are thrown into PC analysis, which seems to be their main working tool:

Fig. 2
Of course PC analysis is limited in its ability to discern and can only provide a very rough view. In any case, here we have PC2/CV2 occupied by intra-modern variability, while only PC1/CV1 show anything that resembles modern-archaic differences: a totally unilinear analysis in the end.
As we know, sample size matters; but instead of balancing it by reducing the number of modern samples (grey dots), the authors have totally ignored this matter. 
So we get an (unclearly legitimate) linear archaic-modern horizontal dimension in which some individuals typically considered Homo sapiens of archaic traits (magenta and black triangles) tend to occupy intermediate positions between the erectus-neanderthal-heidelbergensis conglomerate (left) and the modern human oversized sample (right). Iwo Eleru (IE, black cross) is within this “ambiguous” group and resembles other archaic H. sapiens from the Middle Paleolithic (magenta triangles), as well as similarly aged Upper Cave 101, from North China. 

UC 101 (UC1, pictured left) is a great counter-example because with Jebel Irhoud or the Palestinian skulls, there’s always someone claiming archaic admixture, typically with Neanderthals. But Upper Cave individuals are invariably described as modern in spite of their low vaults, so similar to those of “archaic” Homo sp. A good reason is that they have clear, unmistakably modern, chins.
To me, the calvarium looks very similar in shape to Iwo Eleru. To be safe I compared them both using fig. 4-A as tool:
Inner drawing: Iwo Eleru, outer drawing: modern mean
The comparison may be a bit imperfect but it is clear that the shape of both calvaria, of similar age, one from West Africa and the other from East Asia, are very much alike – and both are somewhat different from the modern mean.
I think therefore that at least serious doubt must be casted on the conclusions that some want to extract from this paper: that there was some sort of archaic hominin in West Africa until recently. Nothing in this data suggests this, instead it does suggest that a better methodology is much needed.

The gene that affects behavior but only if culture allows

This is the interesting story on an SNP demonstrated (statistically significant) to influence behavior among white US citizens. The gene in question is OXTR and the effective SNP is rs53576.
People with two G alleles are more likely to seek emotional support if needed than people with one or two A alleles. But it’s not just generic people… it is white undergraduate US-Americans, who may differ both culturally and genetically from other peoples.
For a change researchers did realize this problem and compared with a Korean sample. Koreans did not display this difference in behavior. So the allele behaves differently in US citizens of European ancestry than in Korean ones.
The question then became: is this ethnic difference caused by different cultural norms or different genetic pools or a combo of both. The answer would come from Korean-Americans: these behave almost identically to European-Americans and quite differently from Koreans in their home country. The result indicates that, while the allele induces a difference in behavior, the expression or blockade of this genetic expression is caused essentially by cultural norms: looking for emotional support is not favored in Korean culture and therefore Koreans raised at their homeland cannot not freely express this allele’s push.
Culture hence shows that it can be dominant over genes. However that is not necessarily a good thing.
This is the summary on the allele’s behavior recycled from Not Exactly Rocket Science, the reference paper being:
But the rs53576 in its G allele has some other curious psychological impacts as revealed by previous papers: people carrying this variant are better able to discern emotional states in others (ref), it affects loneliness and intelligence (ref) and also parenting skills (ref).

Posted by on September 19, 2011 in human culture, human genetics, psychology