A more focused evaluation of R-M269 aging and its implications

[Mikewww]

Alan has often commented, quite correctly, that if we had more confidence in TMRCA estimates for R-M269 and its subclades we could do a much better job of pinning them to various cultural horizon expansions.

There is a new paper out that assessed multiple mutation rate methodologies to try to answer this specific issue.

Jean Manco has already reviewed it. Here is what she has to say. The link to the paper is included.

Per Sjödin and Olivier François have bravely pointed out the obvious in a new paper.* Whether the spread of R1b1b2 (R-M269) can be connected to the spread of farming depends on which mutation rate is used. If the evolutionary mutation rate is favoured, R1b1b2 could be linked to the Neolithic, but germline mutation rates point to a more recent expansion. See The dating game (http://dna-forums.org/index.php?/blog/2/entry-155-the-dating-game/) for the current state of debate over these rates.

This discussion has been common currency on these forums for many moons, but courage is required to go into print with a thought that could outdate almost everything previously published on R1b1b2 in peer-reviewed journals. Not that they come to a firm conclusion as to the date of R1b1b2's gallop across Europe. That is wise. We need more ancient DNA. At present we have a tiny number of samples of Y-DNA from Neolithic sites in Europe, in which haplogroup G2a predominated, and no R1b has turned up. See Y-DNA from Late Neolithic France (http://dna-forums.org/index.php?/blog/2/entry-157-y-dna-from-late-neolithic-france/).

As things stand, the authors recognise that some may interpret their findings as evidence in favour of  evolutionary mutation rate. The Neolithic, which brought a dramatic change of life-style to Europe, has been seen by many as the most likely time for significant population replacement. In my view there is plenty of evidence that farming was indeed brought into Europe by arrivals from the Near East.  However there are several lines of enquiry that suggest subsequent waves of population replacement or mixture. In some places it seems that they almost obliterated the signs of earlier peoples. But we await more evidence from the bones of our ancestors.

* Per Sjödin and Olivier François, Wave-of-Advance Models of the Diffusion of the Y Chromosome Haplogroup R1b1b2 in Europe (http://dx.doi.org/10.1371/journal.pone.0021592), PLoS ONE 6(6): e21592.

[Maliclavelli]

I have read the paper, sent me by my friend Giuseppe Belgeri. It seems to me that the authors take in consideration only three hypotheses about the origin of R1b1b2: Spain, Italy and Asia Minor (today Turkey). I said to my friend that this will be the fifth title for Italy (for those who don’t practise foot-ball, I can say that Italy won 4 titles so far).

[Heber]

There is an interesting article in this months National Geographic on Gobekli Tepi.
This is in Anatolia not far from the source of the Tigris and Euphrates.
Could this have been the home of M269 or its ancestors P297 and P25.

http://ngm.nationalgeographic.com/2011/06/gobekli-tepe/mann-text/1

"Before them are dozens of massive stone pillars arranged into a set of rings, one mashed up against the next. Known as Göbekli Tepe (pronounced Guh-behk-LEE TEH-peh), the site is vaguely reminiscent of Stonehenge, except that Göbekli Tepe was built much earlier and is made not from roughly hewn blocks but from cleanly carved limestone pillars splashed with bas-reliefs of animals—a cavalcade of gazelles, snakes, foxes, scorpions, and ferocious wild boars. The assemblage was built some 11,600 years ago, seven millennia before the Great Pyramid of Giza. It contains the oldest known temple. Indeed, Göbekli Tepe is the oldest known example of monumental architecture—the first structure human beings put together that was bigger and more complicated than a hut. When these pillars were erected, so far as we know, nothing of comparable scale existed in the world."

"At first the Neolithic Revolution was viewed as a single event—a sudden flash of genius—that occurred in a single location, Mesopotamia, between the Tigris and Euphrates Rivers in what is now southern Iraq, then spread to India, Europe, and beyond. Most archaeologists believed this sudden blossoming of civilization was driven largely by environmental changes: a gradual warming as the Ice Age ended that allowed some people to begin cultivating plants and herding animals in abundance. The new research suggests that the "revolution" was actually carried out by many hands across a huge area and over thousands of years. And it may have been driven not by the environment but by something else entirely."