Neanderthal genome confirm very old divergence between both species

This is something that I had oversighted on my first reading of Green-2010:

Assuming an average DNA divergence of 6.5 million years between the human and chimpanzee genomes, this results in a point estimate for the average divergence of Neandertal and modern human autosomal DNA sequences of 825,000 years. We caution that this is only a rough estimate because of the uncertainty about the time of divergence of humans and chimpanzees.

I must say that it is a pretty decent age that correlates well enough with the archaeological record. Acheulean technology, which surely reflects this divergent episode, spread from Africa to Eurasia c. 900,000 years ago or maybe even earlier (1.4 million years in Palestine).

I have mentioned in the past that the actual time of Pan-Homo divergence must be in fact somewhat older, at least 8 million years (ref. Caswell 2008), the difference with the date used by Green is enough to push the Neanderthal-Sapiens divergence to almost 1 million years, right in time to fit with the Acheulean expansion.

I have been advocating for this scenario for some time now and finally it seems that I was right in this. However I still see a lot of people happily talking of a mere 300 Ka, what is simply ridiculous.

This has of course implication for the mtDNA of the Denisova finger, which is doubly old and hence from c. 2 million years ago, from the very spread of H. erectus.

This is important because, against some speculations in the opposite direction, these ages match almost perfectly with the archaeological record: the puzzle fits well and that makes me happy.


The other age estimate is not Green's one

Contradictorily, in a later section they report, using a different method, a divergence age between 270 and 440,000 years. I can only shake my head before this apparent inconsistency. It's worth to read the confusing method they used to reach to this age at the Supporting Online Material (section 14, page 122) because the method produces very strange (and rather very short) age estimates for humans, such as 5000-60,000 for the divergence between Han and Yoruba. I think it's a rather suspicious method that is not better in anything to the point estimate above.

The fact that this procedure was made by co-author Heng Li (from MIT-Harvard, not the main Max Planck Institut team) and that the whole section seems strangely contradictory with the first one (whose SOM article is authored by Green himself - section 10, page 56) makes me think in possible disputes between the authors on which method and result is best, somehow resulting in this patchy double conclusion.

I understand that the estimate of 850 Ka is authored by Green and hence essentially the position of the European team and that the low estimate was introduced in the last minute to satisfy the Americans (after all Science is a US publication and its executive publisher has connections with the MIT).

I wonder which is the ideological or camarilla interest in promoting and even force-feed, as in this case, these low age estimates against all common sense, it is beginning to stink.

Acheulean spread from Africa to Eurasia

Important paper the one that David Beard mentions at Archaeology in Europe:

Stephen J. Lycett, Understanding Ancient Hominin Dispersals Using Artefactual Data: A Phylogeographic Analysis of Acheulean Handaxes. PLoS ONE, 2009. (Open Access).

Lycett analyzes the structure of Acheulean handaxes of Africa and Eurasia and concludes that there is very strong support (>94% likelihood) for an out-of-Africa scenario.

In all maximum parsimony trees, Eurasian axes appear as derived from African ones, possibly indicating that a migration (H. erectus or H. ergaster, depending on your naming preferences) from Africa to Eurasia happened along that techno-cultural spread.

Acheulean was first developed in Africa, some 1.6 million years ago. The most ancient confirmed date for Eurasian Acheulean is that of 'Ubeidiya (Palestine), dated to c. 1.4 million years ago though often thought of as a penetration without further consquences, followed by European ones (southern Spain, c. 900,000 BP) and more recent ones (c. 780,000 BP) in Palestine and other European areas (c. 600,000 BP). South Asian Acheulean is less well dated but most findings seem to be older than 800,000 BP.

However in Lycett trees, South Asian handaxes' typology appears consistently as older than European one (but more recent than the African types). He does not seem to have analyzed the very old Iberian or Palestinian tools though.
.

Acheulean much older than thought in Europe

Martín Cagliari's blog, Mundo Neandertal, brings me to a quite interesting discovery: Acheulean findings of Iberia are much older than believed so far.

The sites of Solana de Zamborino (Granada) and Cueva Negra (Murcia) happen to be much older than believed so far. Until now these sites had been dated only based on their industry style, and therefore believed to have been from 400,000 BP on but the new sutdy by Gary R. Scott and Luis Gibert has found that, on geochronological grounds, the findings must be dated to c. 900,000 (Cueva Negra) and 780,000 BP (Zamborino).

This pushes the arrival of Acheulean to Europe back to the same date as the (believed) arrival of Pebble Culture and the oldest known H. erectus in the area (Homo georgicus, dated to c. 800,000 BP, considered intermediate between H. habilis and H. erectus, it seems).


Primitive navigation?

It also raises again the issue of whether H. erectus could have crossed the Gibraltar Strait from Africa to Europe. This was already believed based on the fact that both Pebble and Acheulean tools are found earlier in southern Iberia than further north.

But Gibraltar Strait was never totally closed in the Ice Age, so these Erectus people must have built some sort of boats or rafts to cross it. The other case suggesting some sort of boating skills in hominins is found at the other corner of Eurasia: in Flores. Homo floresiensis arrived to a remote island in Indonesia (also never directly linked to the contintent) somehow and surely it was not by means of mere swimming (how could whole bands do that, with children and everything?). These two seem to be the major documented feats of navigation by Homo species other than ours (for some reason, Neanderthals don't seem to have done anything of the like - the Bosphorus at best).


References:
· “The oldest hand-axes in Europe”. Gary R. Scott & Luis Gibert. NATURE| Vol 461|3 September 2009.
· EFE news article.
.