June 21, 2013

Origins and dispersals of Y-chromosome haplogroup N

I will simply note that the authors use the effective mutation rate that is ~1/3 the genealogical mutation rate and hence their age estimates are inflated by ~3x. I have expressed reservations about using Y-STR based age estimates in general, but these concerns become more important for older lineages.

In particular, I would be very surprised if Y-haplogroup N turns up in Europe 8-10 thousand years ago, and I expect to see it make its first appearance in the 3rd millennium BC or thereabouts, perhaps together with the Seima-Turbino expansion across northern Eurasia. Thanks to the ancient DNA -preserving boreal cold, it may be possible to find out.

Irrespective of my disagreement on the mutation rate issue, I have to applaud the comprehensive survey carried out by these Chinese scientists: numbers invariably pay off.

PLoS ONE 8(6): e66102. doi:10.1371/journal.pone.0066102

Genetic Evidence of an East Asian Origin and Paleolithic Northward Migration of Y-chromosome Haplogroup N

Hong Shi et al.

The Y-chromosome haplogroup N-M231 (Hg N) is distributed widely in eastern and central Asia, Siberia, as well as in eastern and northern Europe. Previous studies suggested a counterclockwise prehistoric migration of Hg N from eastern Asia to eastern and northern Europe. However, the root of this Y chromosome lineage and its detailed dispersal pattern across eastern Asia are still unclear. We analyzed haplogroup profiles and phylogeographic patterns of 1,570 Hg N individuals from 20,826 males in 359 populations across Eurasia. We first genotyped 6,371 males from 169 populations in China and Cambodia, and generated data of 360 Hg N individuals, and then combined published data on 1,210 Hg N individuals from Japanese, Southeast Asian, Siberian, European and Central Asian populations. The results showed that the sub-haplogroups of Hg N have a distinct geographical distribution. The highest Y-STR diversity of the ancestral Hg N sub-haplogroups was observed in the southern part of mainland East Asia, and further phylogeographic analyses supports an origin of Hg N in southern China. Combined with previous data, we propose that the early northward dispersal of Hg N started from southern China about 21 thousand years ago (kya), expanding into northern China 12–18 kya, and reaching further north to Siberia about 12–14 kya before a population expansion and westward migration into Central Asia and eastern/northern Europe around 8.0–10.0 kya. This northward migration of Hg N likewise coincides with retreating ice sheets after the Last Glacial Maximum (22–18 kya) in mainland East Asia.



Dr Rob said...
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Va_Highlander said...

If their suggested chronology is off by a factor of three, then the expansion northward would fall not too long after the domestication of rice, presumably in southern China.

terryt said...

"The highest Y-STR diversity of the ancestral Hg N sub-haplogroups was observed in the southern part of mainland East Asia, and further phylogeographic analyses supports an origin of Hg N in southern China".

I have difficulty seeing that. And I'm not the only one it seems. Skywalker wrote at Zetaboards:

"If N originated in southwestern-southern China 20K ago, why isn't there any N* in Austro-Asiatics when there are in Northern Han and even Altaics?"

Yes. Difficult to explain. It looks far more likely to me that N in southern China is a result of more recent southward movement from around the Sichuan/Tibet border region. N1-LLY22g makes up 30% of Y-DNA in Sichuan according to Wiki:


Also note that the nomenclature and phylogeny is somewhat different from that of ISOGG. N-M46 is now N1c1 (N1c in the paper), N-M128 is now N1c2a ((N1a) and N-P43 is now N1c2b (N1b).

Jaska said...

Dr Rob:
"N1b: older and less 'star-like' expansion suggests Holocene/ Neolithic expansion from China to Siberia. But keep in mind also that Malyarchuk suggests that N1b might be older on the "european" side c.f. Asian-Siberian side, supported by Mirabal"

N1b (N1c2b) cannot be older in Europe. This is only a bogus created by the diversity: in Europe there are both European and Asian lineages, while in Asia there are only Asian lineages (= smaller diversity).

All that matters is: which lineage is ancestral?

Dr Rob:
"N1c: perhaps related to the Seima-Turbino phenomenon, but that's only if you believe that S-T was spread by a population movement. This, of course, has come under significant critique"

There are no Seima-Turbino settlements or "culture", only bronze artifacts found in the settlements of other, local cultures. This makes it certain that the phenomenon was spread by mobile traders, not by cultural diffusion.

I agree with Dienekes on the Bronze Age dating of arrival of N1c1 to the Baltic Sea region.

bicicleur said...

10 ky BP in Northern Europe seems to match with Kunda culture

Diogenes said...

So far these movings are exact, what is the actual genetic of Phenotypes able to make understand how the Phenotypes evoluated with these migrations..Difficult to see a Baltic heir of South East China..?!