May 16, 2008

Paternal genetic structure of Hainan Islanders

Hainan Island on Wikipedia.

PLoS ONE. 2008 May 14;3(5):e2168.

Paternal genetic structure of Hainan aborigines isolated at the entrance to East Asia.

Li D, Li H, Ou C, Lu Y, Sun Y, Yang B, Qin Z, Zhou Z, Li S, Jin L.

BACKGROUND: At the southern entrance to East Asia, early population migration has affected most of the Y-chromosome variations of East Asians. METHODOLOGY/PRINCIPAL FINDINGS: To assess the isolated genetic structure of Hainan Island and the original genetic structure at the southern entrance, we studied the Y chromosome diversity of 405 Hainan Island aborigines from all the six populations, who have little influence of the recent mainland population relocations and admixtures. Here we report that haplogroups O1a* and O2a* are dominant among Hainan aborigines. In addition, the frequency of the mainland dominant haplogroup O3 is quite low among these aborigines, indicating that they have lived rather isolated. Clustering analyses suggests that the Hainan aborigines have been segregated since about 20 thousand years ago, after two dominant haplogroups entered East Asia (31 to 36 thousand years ago). CONCLUSIONS/SIGNIFICANCE: Our results suggest that Hainan aborigines have been isolated at the entrance to East Asia for about 20 thousand years, whose distinctive genetic characteristics could be used as important controls in many population genetic studies.

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8 comments:

Maju said...

It is quite an interesting study thanks.

I find it most striking the really old age estimates for Hainanese O1a* and O1b*, of more than 30 KY. If real, the usual O, NO, K and F age estimates should be pushed further back in time probably.

Ebizur said...

maju said, "I find it most striking the really old age estimates for Hainanese O1a* and O1b*, of more than 30 KY."

The most common haplogroups among the Hlai are O2a*-M95(xO2a1-M88/M111) and O1a*-M119, not "O1a* and O1b*." The average frequency of haplogroup O2a* among Hlai people is 212/327 = 64.83%, ranging from 23/50 = 46.00% O2a* among the Jiamao subgroup of the Hlai to 57/62 = 91.94% O2a* among the Gei subgroup. In addition to these extremely high frequencies of haplogroup O2a-M95, the Hlai also have a low frequency (average 8/327 = 2.45%) of haplogroup O2(xO2a-M95), but these O2(xO2a) Y-chromosomes were unfortunately not tested for any of the markers that define haplogroup O2b. Besides haplogroup O2a, the only other Y-DNA haplogroup that has a major presence among the Hlai people of Hainan is haplogroup O1a*-M119 (average 85/327 = 25.99%). In other words, about two thirds of Hlai males belong to haplogroup O2a*-M95, another quarter of Hlai males belong to haplogroup O1a*-M119, and the rest belong mainly to haplogroup O3-M122 (average 16/327 = 4.89%), haplogroup O2-P31(xO2a-M95) (average 8/327 = 2.45%), and haplogroup C3-M217 (average 4/327 = 1.22%). It is interesting that the non-O1a/O2a Y-DNA among the Hlai has a distribution more similar to that of modern Koreans than to that of modern Han Chinese; this might suggest that the Hlai have not mixed at all with the Hans and that their non-O1a/O2a component is derived rather from Proto-Koreans, or else that the non-native admixture in Hlai is derived from some group of Han Chinese that had a Y-DNA composition very similar to that of modern Koreans.

The Y-DNA composition of the Cun people was very different from that of the Hlai. The Cun people belonged mostly to haplogroup O1a* (45/78 = 57.69%), with haplogroup O2(xO2a), which might actually be haplogroup O2b in part or in whole, in second place with 14/78 = 17.95%, and haplogroup O3 in third place with 12/78 = 15.38%. Amazingly, haplogroup O2a* was found in only 3/78 = 3.85% of Cun people, which makes it even less common among them than haplogroup C3 (4/78 = 5.13%).

Unknown said...

O2a-M95 age and origin are still under discussion. some times they lead to little controversy.
It is mainly concentrated in SE Asia from India , Indonesia , Malaysia etc.
There was a paper saying it's highest diversity is in India.

Maju said...

The most common haplogroups among the Hlai are O2a*-M95(xO2a1-M88/M111) and O1a*-M119, not "O1a* and O1b*."

Sure. My bad.

It is interesting that the non-O1a/O2a Y-DNA among the Hlai has a distribution more similar to that of modern Koreans than to that of modern Han Chinese; this might suggest that the Hlai have not mixed at all with the Hans and that their non-O1a/O2a component is derived rather from Proto-Koreans, or else that the non-native admixture in Hlai is derived from some group of Han Chinese that had a Y-DNA composition very similar to that of modern Koreans.

I am not sufficiently educated in haplogroup O to judge, so I'll take your word on that. The proto-Korean explanation seems more plausible to me maybe.

The Y-DNA composition of the Cun people was very different from that of the Hlai.

They cluster with northern peoples like Han, Tibeto-Burmans and "Altaic" in the PC graph. Taiwanese aborigines do too.

I don't really know what to think of the similitude in O1a* and difference in O2a* apportions, that is most extreme if you compare the Cun with the Gei (these two are almost inverse in these two clades). The Gei could maybe represent a "purer" (or "purified" by drift) version of Hlai, with zero presence of other clades than O1a* and O2a*. Their geographical position also seems more isolated, in the interior SE of the island.

But the presence of possible O2b (O2*) among the Cun suggests again a Korean or Japanese connection, right?

Ebizur said...

I am not sufficiently educated in haplogroup O to judge, so I'll take your word on that. The proto-Korean explanation seems more plausible to me maybe.

Koreans have approx. 40% ~ 50% haplogroup O3, approx. 20% ~ 30% haplogroup O2b, and approx. 12% ~ 16% haplogroup C3 according to studies that I have seen. Han Chinese practically lack haplogroup O2b and have relatively little haplogroup C3 (approx. 4% ~ 8% on average, although the frequency of haplogroup C3 among Hans in parts of northwestern China and central China is actually quite high), while almost all subgroups of Han have more than 50% haplogroup O3. In the case of the Hlai on Hainan, however, the frequency of haplogroup O3 is exactly twice that of haplogroup O2(xO2a), and the frequency of haplogroup O2(xO2a) is exactly twice that of haplogroup C3, which is rather similar to the proportions of these haplogroups in the Korean population.

They cluster with northern peoples like Han, Tibeto-Burmans and "Altaic" in the PC graph. Taiwanese aborigines do too.
I generally ignore anything that researchers have grouped as "Altaic," because I think that it is a spurious category.

But the presence of possible O2b (O2*) among the Cun suggests again a Korean or Japanese connection, right?
O2(xO2a) might, but does not necessarily, belong to haplogroup O2b. I just wish that the researchers had tested a marker of haplogroup O2b so we would have a certain answer to this question.

Maju said...

You make a lot of sense with that comparison of Korean and Hlai Y-DNA approtions. Hopefully the issue will be researched more in depth in the future.

I was trying to find out something more about these peoples, specially the Cun, but there's not much stuff on the usual generalist sites like Wikipedia (the Cun are not even mentioned). Ethnologue though has something and classifies both languages, Hlai and Cun, as Tai-Kadai; Hlai in its own branch and Cun as Kadai > Yang-Biao (together with four other ailing languages of Vietnam and Yunnan). Cun language seems to share some 40% of its vocabulary with Hlai anyhow.

As for "Altaic" I can just guess they mean Turco-Mongol, what is a somewhat valid usage of the term (micro-Altaic theory, excluding Korean and Japonic, has been revived lately).

Ebizur said...

"I was trying to find out something more about these peoples, specially the Cun, but there's not much stuff on the usual generalist sites like Wikipedia (the Cun are not even mentioned). Ethnologue though has something and classifies both languages, Hlai and Cun, as Tai-Kadai; Hlai in its own branch and Cun as Kadai > Yang-Biao (together with four other ailing languages of Vietnam and Yunnan). Cun language seems to share some 40% of its vocabulary with Hlai anyhow."

Another recent paper on the subject of Daic-speaking peoples, whose production team included some of the same members (e.g. Li Hui, Li Jin) as the study which we have been discussing here, reported data on the Hlai (Qi/Gei and Jiamao subgroups) and Cun that were quite different:

Hlai (Qi/Gei):
12/34 = 35.3% O(xO1a, O2a, O3)
11/34 = 32.4% O1a(xO1a2)
10/34 = 29.4% O2a(xO2a1)
1/34 = 2.9% O3a5a

Hlai (Jiamao/Kamau):
7/27 = 25.9% O(xO1a, O2a, O3)
14/27 = 51.9% O1a(xO1a2)
6/27 = 22.2% O2a(xO2a1)

Cun:
1/31 = 3.2% C
2/31 = 6.5% K(xM, O, P)
3/31 = 9.7% O(xO1a, O2a, O3)
12/31 = 38.7% O1a(xO1a2)
12/31 = 38.7% O3(xO3a1, O3a4, O3a5)
1/31 = 3.2% O3a5a

These other data show a higher frequency of O(xO1a, O2a, O3), which is potentially O2* or O2b, among Hlai than among Cun. The two sets of data agree on the near-absence of haplogroup O2a-M95 among the Cun, though.

"As for "Altaic" I can just guess they mean Turco-Mongol, what is a somewhat valid usage of the term (micro-Altaic theory, excluding Korean and Japonic, has been revived lately)."

What about the Manchu-Tungus languages, then? Would they be included in this newly revived version of "Altaic"? I have serious doubts that Altaic will ever be established as a language family exclusive of various other languages of Eurasia and beyond that are usually not considered in the scope of "Altaic."

Maju said...

Intersting, thanks. Just watch out that identification of O* with O2b is not just wishful thinking or pattern-recogniton instict. It's a pity that budget seems to limit the number of SNPs tested in these studies.

As for Altaic, certainly Manchu-Tungus too. Just that being a smaller group I forgot. I don't really know if micro-Altaic will survive the test of time and criticism but at least seems a more valid usage of the term "Altaic" than in macro-Altaic, pretty much discredited by now.