Monday, June 9, 2014

New Archaic Y-DNA R1b In Southern Siberia?

A recent comment at the Eurogenes blog states:
"Two out of three afanasievo remains and one okunevo remains tested R1b1 (M269) and one afanasievan – R1b."

Source (in russian) :
The Afansevo culture, which appears to be the one referred to in the post above:
is the earliest Eneolithic archaeological culture found until now in south Siberia, occupying the Minusinsk Basin, Altay and Eastern Kazakhstan.

Conventional archaeological understanding tended to date at around 2000–2500 BC. However radiocarbon gave dates as early as 3705 BC on wooden tools and 2874 BC on human remains. The earliest of these dates have now been rejected, giving a date of around 3300 BC for the start of the culture.

The culture is mainly known from its inhumations, with the deceased buried in conic or rectangular enclosures, often in a supine position, reminiscent of burials of the Yamna culture, believed to be Indo-European. Settlements have also been discovered. The Afanasevo people became the first food-producers in the area by breeding cattle, horses, and sheep. Metal objects and the presence of wheeled vehicles are documented. These resemblances to the Yamna culture make the Afanasevo culture is a strong candidate to represent the earliest cultural form of a people later called the Tocharians.

The culture became known from excavations in the Minusinsk area of the Krasnoyarsk Krai, southern Siberia, but the culture was also widespread in western Mongolia, northern Xinjiang, and eastern and central Kazakhstan, with connections or extensions in Tajikistan and the Aral area.

The Afanasevo culture was succeeded by the Andronovo culture as it spread eastwards, and later the Karasuk culture.
The link of the Afansevo culture to the Tocharians is made, for example, in J.P. Mallory and Victor H. Mair, The Tarim Mummies: Ancient China and the Mystery of the Earliest Peoples from the West (2000).

There are more than a dozen rural Russian villages or settlements called "Okunevo", and presumably the one referenced above is geographically is a Southern Siberian site near the Afansevo finds in a reasonably similar time frame.

One way to read the reference is that three out of three Afansevo remains and one set of nearby in time and place Okunevo remains all had Y-DNA haplogroup R1b, with all but one having enough preservation of the ancient DNA to subtype it as R1b (M269), the predominant Western European subclade of R1b, and the other insufficiently preserved to be more specific than an R1b classification generally.

Mallory made the case in a 2011 talk that R1b was a Tocharian genetic signature based upon West Eurasian Y-DNA haplogroups found in Uyghur populations that were direct successors to and brought about the fall of the Tocharians during a period of Turkic expansion. But, ancient Tarim mummy DNA from ca. 1800 BCE, analyzed in 2009 showed uniformly R1a1a Y-DNA haplogroups (citing Li, Chunxiang. "Evidence that a West-East admixed population lived in the Tarim Basin as early as the early Bronze Age". BMC Biology (February 17, 2010)), so any Y-DNA R1b in that population would have to have entered that gene pool sometime in the following 2400 years or so, and was apparently not present initially.

This would be very notable as there are no other instances of ancient Y-DNA R1b so far East, particularly in a population strongly presumed to be Indo-European ca. 3300 BCE.

There are many ancient Y-DNA samples from Siberia and other parts of the Russian Steppe around that time or a bit later that are overwhelmingly R1a (including ancient Y-DNA from individuals who were part of the Andronovo culture that followed the Afansevo culture, suggesting that the later specifically Indo-Iranian culture may have replaced Afansevo, rather than evolving from Afansevo) or have Y-DNA Q, a sister Y-DNA clade to R.  But, there are no ancient Y-DNA samples to my knowledge that are consistently R1b or even R1b at all, in that region.

Today, R1b-M269 is predominant in large swaths of Western and Northern Europe where it expanded fairly recently (see, e.g. haplogroup and subhaplogroup mutation rate based age estimates here). It is also found in Armenians, Turks, north Iranians, and Lezgins among others (basically, West Asians).

The oldest known ancient Y-DNA R1b sample is from a late Copper Age Bell Beaker culture individual in Germany ca. 2800 BCE to 2000 BCE.

Circumstantial evidence and the phylogeny of Y-DNA haplogroup R1 strongly points to an ultimate origin of the haplogroup well to the east of the places where Y-DNA R1b is most common today, but just where has never been pinned down very definitively. Ma'alta boy with Y-DNA R* from ca. 24,000 years ago around the Altai pushes potential Paleolithic spread of R* far to the East, but triangulations from R2 in South Asia, R1a focused in Central and Eastern Europe into Siberia, and R1b in Western Europe (possibly as a late arrival from what is now Czech territory), has favored an origin around the Caucasus mountains or West Asia or Central Asia with no hint of an Eastward expansion for R1b in recent prehistory.

Of course, a mention in a Russian language blog post that I am relying on a second hand translation of, when another Eurogenes commentator doubts the workmanlike quality of the investigators involved, in and of itself, is not exactly authoritative and stinks of mere rumor. But, the rumor is specific and plausible enough (and my cynicism regarding the quality of work done by ancient DNA researchers is not so great) that I think it deserves a mention.

I've previous stated, repeatedly, that I believe that R1b in Europe was spread by a linguistically non-Indo-European culture (probably part of the same language family as the modern Basque language) whose speakers only later converted linguistically to Indo-European languages, mostly by proto-Celtic and proto-Germanic populations around and after Bronze Age Collapse ca. 1,200 BCE. Other investigators have argued that R1b was spread by Indo-Europeans, probably quite a bit earlier.

If Y-DNA haplogroup R1b was common or even predominant in the Afansevo culture, however, it becomes more plausible both that Afansevo was not Indo-European, and that the peoples who spread R1b in Europe were linguistically Indo-European people who were descended from or historically related to the Afansevo people, although none of this would be definitive.

UPDATE:  A blog post here from July 13, 2013, analyzing a recent paper on modern Y-DNA distributions in Central Asia that notes R1b-M269 in Turkmen and Uzbek populations of Central Asia (but not in other Central Asian and Siberian populations) that are probably not the product of recent historic flukes, adds useful data points when evaluating these questions.  The R1b-M269 in those areas could very plausible have origins in Afansevo populations.  Of course, it is still more common in the Caucasus (Armenians, Azeris, Georgians, Ossetians).

1 comment:

andrew said...

The R1a-R1b split dated by mutation rates to about 24,000 years ago, coincides with the early onset of the Ice Age that gave rise to the Last Glacial Maximum. This suggests that the split would have arisen in populations split up and bottled up in Ice Age refugia.