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Population movements to the Himalayas; y-chromosomal perspective
Topic Started: Apr 5 2007, 06:58:24 PM (839 Views)
black man
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A new paper by Gayden et al. was published. They suggest about 5000 years of age for y hg D1 and about 11.000 years for hg D3 as for their sample. This sample 156 Tibetans. However, they do not mention the concrete origins of these men. Thus, the sample could be biased towards certain regions within the Tibetan cultural sphere.

Since hg D1 was so far associated with several East Asian ethnic groups, I suppose that it is not unlikely to really reflect a proto-Tibeto-Burman population expansion among others. Hg D3 was so far restricted to High Asian samples (see supplementary material of Hammer et al. 2006). Also, its frequency in Tibetans is apparently generally higher than that of D1. It might thus be a relic of "pre-Tibetans".

See their text for more migration theories.
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Maju
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sorgina
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Do we know (archeologically speaking) when was the Tibetan plateau colonized. In the Ice Age it was probably quite deserted (boreal/alpine desert) and therefore I would expect the area to have been colonized in the epi-Paleolithic or even Neolithic period. What does archeology say about this issue?

In case I'm correct, proto-Tibetans (carriers of D1 and D3, among other haplogroups) should have dwelt somewhere else in the UP. Where? Form the extension of D1, Central Asia could be a candidate but from the linguistic viewpoint, Northern China region seems more logical (i.e. Sino-Tibetan is a consolidated linguistic family).

Any data or ideas?
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ren
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Quote:
 
Do we know (archeologically speaking) when was the Tibetan plateau colonized. In the Ice Age it was probably quite deserted (boreal/alpine desert) and therefore I would expect the area to have been colonized in the epi-Paleolithic or even Neolithic period. What does archeology say about this issue?

It was colonized around 15,000 years ago, as I remember. Studies can be found here,
http://s6.invisionfree.com/orient/index.php?showtopic=752
http://z6.invisionfree.com/orient/index.php?showtopic=1133.
The initial colonization seems to be in the lower altitudes, and in temporary arrangements. In any case, occupation of Tibet is older than a proto-Sino-Tibetan language.

Quote:
 
In case I'm correct, proto-Tibetans (carriers of D1 and D3, among other haplogroups) should have dwelt somewhere else in the UP. Where? Form the extension of D1, Central Asia could be a candidate but from the linguistic viewpoint, Northern China region seems more logical (i.e. Sino-Tibetan is a consolidated linguistic family).

As I've said before, D does not appear to be indigenous nor a usual lineage in Central Asia, unless you mean central Asia.

It is possible that D1 and D3, and D* were the orginal lineages. In Tibetans, very curly hair is not unusual, and this might have something to do with D carriers. The archaeological context is that of a North Asian one, so it seems people moved into Tibet from NW China proper, and such techno-complexes seem to be ultimately derived from Central Asia, so it is possible that D came via Central Asia and was subsequently lost there, just as D in the Andamans came via South Asia but was subsequently lost in South Asia. That would make the origination of D to be before Central and South Asia, in SW Asia perhaps but was subsequently lost there.

I had originally thought D was of a southern origin based on D* in the Andamans and some popular theories about the Ainu and Jomon, but since the archaeology does not give evidence to this (although some does, I've found, link), it's possible that D came into ASia in atleast 2 separate routes, which is very interesting.
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black man
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Maju
Apr 6 2007, 01:52 PM
Do we know (archeologically speaking) when was the Tibetan plateau colonized. In the Ice Age it was probably quite deserted (boreal/alpine desert) and therefore I would expect the area to have been colonized in the epi-Paleolithic or even Neolithic period. What does archeology say about this issue?


Gayden et al. write 30.000 years ago or so.

Quote:
 
In case I'm correct, proto-Tibetans (carriers of D1 and D3, among other haplogroups) should have dwelt somewhere else in the UP. Where? Form the extension of D1, Central Asia could be a candidate but from the linguistic viewpoint, Northern China region seems more logical (i.e. Sino-Tibetan is a consolidated linguistic family).

Any data or ideas?


In contrast to hgs D1 and O3, hg D3 seems to be exotic to East Asians. "D3"'s distribution is exclusively High Asian as far as one can conclude from the available data. I.e. its first carriers might have been physiologically different from those carriers of hg O3 and D1 today whom we know to look "East Asian". Considering the physiological diversity of palaeolithic humans, a separation of the carriers from East Asians would have resulted in a completely different phenotype after 10.000 years.

IMO it can be expected that hg D3 went through at least one bottleneck effect before being absorbed by Tibeto-Burman speakers. So it is nowadays not associated with any phenotype completely different from that of East Asians. When, how often and where the isolation of hg D3 from East Asian hgs ended is unclear.

The STR diversity of "D3" indicates that it might have gone through a bottleneck about 10.000 years ago, if it's really the maximum diversity they got in this the study of Gayden et al. Gayden et al. don't go into detail about this. Instead, they propose para-hg(!) O3-M134+, M117- to be the oldest in Xizang with more than 20.000 years. But that's a para-hg and not unlikely consist of several, still undefined hgs which migrated to the Tibetan plateau either coincidentally together or even totally independently. That means, their time of expansion estimates for the para-hg might not be really relevant for any expansions to Xizang. In general, it's necessary to combine age estimates with SNP studies. If impossible (due to the lack of SNP markers), one will have to use STR networks with data from all related and surrounding populations. And that's what Gayden et al. did not do: their STR samples were restricted to only four populations, which were btw also all relatively closely related to each other.

Hg D1 is expected to reflect something relatively recent like a neolithic expansion by Gayden et al. It was so far never found among foragers but only among populations which can be traced back to recent or neolithic, at best maybe mesolithic, movements into SE Asia. And there only in low frequencies. I.e.: 1) "D1" can be assumed to have been originally a minor component of late East Asian stoneagers, whose descendents are e.g. Hmong-Mien. 2) the high frequencies of "D1" in Tibeto-Burmans are likely due to be a founder effect. 3) "D1" carriers were probably accompanied by "O3" carriers not only today but also in the past.

I find the expansion time estimates for hg O3-M134 in Tibetans too high to be relevant for movements within Xizang. Proto-Tibetans probably lived in founder populations practicing agriculture, i.e. in relatively big communities (unlike e.g. the often y-chromosomally monomorphic steppe dwellers). Judging from the fact that polyandry is still practiced in the region, why shouldn't there have been paternally unrelated men who lived in these founder populations? That would naturally have increased STR diversity from the beginning.
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Maju
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sorgina
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I must say I don't realy like the idea of "monomorphic nomads" and "polymorphic agriculturists", much less relying in a polyandry that (AFAIK) actually has brothers as co-husbands by rule. Also, Mongols and other steppary peoples show at least as much plurality of Y-DNA haplogroups as Tibetans show.

I'd rather imagine that either:

a- Tibet did play a role in the diffusion of D subgroups, hence retaining some specific haplogroups such as D3.

b- D3 become extinct (or nearly so, as much as it has not been detected) elsewhere by accident (genetic drift), while in Tibet (also accidentally) suceeded (along with D1 or not).

Also, if it is correct that Sino-Tibetans migrated to Tibet after it was already populated, I can assume that these were the ones that brought most of O3 and maybe also the D1 element.

D1 in fact seems less certain specially because its direct relation to D3 (Tibet) and D2 (Japan). It would seem to suggest that D carrier populations were in some areas of East Asia before "the great O migration" overwhelmed them.

I'm not sure if we can easily associate these D people to a different phenotype, as Black Man suggests, or rather we should not.
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black man
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Quote:
 
I must say I don't realy like the idea of "monomorphic nomads" and "polymorphic agriculturists", much less relying in a polyandry that (AFAIK) actually has brothers as co-husbands by rule. Also, Mongols and other steppary peoples show at least as much plurality of Y-DNA haplogroups as Tibetans show.


On the tribal level (and that's what nomads are) the observation of paternally homogenous communities can be made. Chaix et al. already illustrated that in two of their papers concerning the nomads of the northwestern steppes. But as soon as nomads become city dwellers, their y-chromosomal haplogroup diversity increases. That has something to do with the social organisation of nomads which is different from that of urbanites.

Maybe you also saw that new paper in which they reported high frequency of y hg N1 in a Kazakh sample. Hg N1 is generally very rare, also in Kazakhs. But in steppe populations such hgs can suddenly pop up as if out of nowhere. That is how explain such phenomena. Actually, I'd be very surprised if they'd report a high STR diversity for y hg N1 in Kazakhs. Or just to name those haplogroup which were already shown to have low STR diversities in nomads and former nomads: R1a1 in Kyrgyz subpopulations and C3 in Pakistani Hazaras.

Quote:
 
I'd rather imagine that either:

a- Tibet did play a role in the diffusion of D subgroups, hence retaining some specific haplogroups such as D3.


Xizang is not really a place from where expansion worked well. The only exception mentioned in historical sources was Xinjiang. And indeed, modern Uighurs carry both hgs D3 and O3-M134 as if Tibetan conquerors had left their descendants among them.

In Mongolia, the only other place where hg D3 was also detected, its percentage is so low that it might have been introduced by captives having worked as servants for the Mongols and/or by libidinous Tibetan monks.

Quote:
 
b- D3 become extinct (or nearly so, as much as it has not been detected) elsewhere by accident (genetic drift), while in Tibet (also accidentally) suceeded (along with D1 or not).


Para-hg D(xD1,D2,D3) was also found in Tibetans, not just in Gayden's sample but also in Hammer's sample published last year. It could in fact include the direct predecessor of hg D3.

Quote:
 
Also, if it is correct that Sino-Tibetans migrated to Tibet after it was already populated, I can assume that these were the ones that brought most of O3 and maybe also the D1 element.


Yes, Xizang is not comparable with Iberia or the British Isles because it primarily consists of rocks. Population density in most of its parts must have been very low before agriculture was introduced. You can compare it with Siberia rather than with Western Europe.

Let's not forget that Tenzin Gayden is Tibetan. His paper is relatively good but still too tibetocentric for my taste. There is a parallel between what Gayden et al. write about Tibetan hg O-M134 and what East Europeans write about R1a1: both trace the high STR diversities of "their" major haplogroups back to local populations. Nevertheless, as Gayden et al. also admit, the situation is more complex: several migration waves are possible. Unfortunate is only that Gayden et al. do not mention the fact that populations with already high STR diversities can migrate, too.

Quote:
 
I'm not sure if we can easily associate these D people to a different phenotype, as Black Man suggests, or rather we should not.


That was not my point.

Again, I want to emphasise that at the moment all available data indicates that hg D3 carriers have been isolated from East Asians, except for those who migrated into Xizang or into the river region which connects Xizang with South and SE Asia. It was not found in any East Asian population. And I'm referring to a sample of 1383 East Asians tested by Hammer et al. Additionally, we can say about what Chinese researchers found out about the y-chromosome of tested eastern Tibeto-Burmans (Tujia) and western Han (who probably absorbed early Tibeto-Burmans) that none of them was in paragroup D(xD1) (correction: except for three men from Xian), i.e. maybe none of them belonged to hg D3. So both the age estimate by Gayden et al. and the geographical distribution of this hg make a central East Asian origin of hg D3 unlikely.

As for hg D1, I already indicated that there is no reason for associating this hg with a different phenotype. It is a haplogroup with little meaning both on the ethno-linguistic and on the regional levels. It is never nearby or above the 50% mark in any sense.

But y hg D2 in the Japanese archipelago is clearly associated with subpopulations which retained relatively much of the pre-Yayoi peoples, including deviating phenotypes: Ainus and Ryukyuans. This indicates that the Japanese archipelago was once so isolated from continental East Asia that a distinct phenotype was retained even till today besides the genetic pecularity of y hg D2... In the case of Tibetan hg D3 the isolated appearance is similar but the frequency of occurence lower...
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Maju
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sorgina
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After consulting with my pillow, I think I can agree that Tibet would seem an apparent source of the D haplogroup. Though the division from E mut have happened either in Central or West Asia and it's, as you say, rather odd that such a sparsely populated region was the source of anything. But Siberia was also the source or point of dispersion of several important haplogroups (N, Q and C3 that I can think right now).

What really hasn't been answered in any satisfactory way is how such D carrier people jumped from Tibet to Japan without leaving any legacy in between other than the small ammounts of D1, if the spread of this haplogroup has any relevane to the issue that doesn't seems clear. I imagine that wider population sampling and analysis will eventually bring to light traces of D(xD1) among East Asians other than Japanese or Tibetans but still it is cler the migration of the "D peoples" has left very little legacy outside of the refuge areas in Tibet and Japan.

...

In a side note: why do you use the Chinese name for Tibet (in Tibetan is "Bod")?. I wonder why you, that so much has complained about ethnical identity being erased by Chinese cultural centralization, now prefer to use ill-known Chinese nationalistic terms instead of the international one.
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the Empire was never founded.
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black man
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Quote:
 
After consulting with my pillow, I think I can agree that Tibet would seem an apparent source of the D haplogroup. Though the division from E mut have happened either in Central or West Asia and it's, as you say, rather odd that such a sparsely populated region was the source of anything. But Siberia was also the source or point of dispersion of several important haplogroups (N, Q and C3 that I can think right now).


Yes, but lately and then only from quite a narrow strip on land between taiga and desert. Siberia can be entered from both the western and the eastern forest zones for those who want to avoid the desert. Similarly, Xizang can be entered along the Brahmaputra, Salween, Irawaddy and Mekong from the south as well as from the Yangtse and Yellow Rivers from the east and some smaller rivers somewhere in the Kashmir/Pakistan region in the west.

Btw, I was also already tired replying yesterday. I have to correct myself above concerning D(xD1) since it was found in the former capital of China, Xian. However, it should be kept in mind that this was really a capital, i.e. it probably attracted people from different regions. So it likely to be not 100% representative for the genome of western Han.

Quote:
 
What really hasn't been answered in any satisfactory way is how such D carrier people jumped from Tibet to Japan without leaving any legacy in between other than the small ammounts of D1, if the spread of this haplogroup has any relevane to the issue that doesn't seems clear. I imagine that wider population sampling and analysis will eventually bring to light traces of D(xD1) among East Asians other than Japanese or Tibetans but still it is cler the migration of the "D peoples" has left very little legacy outside of the refuge areas in Tibet and Japan.


Hammer's sample from 2006 did not include northeastern Han. Northeastern Han were previously shown to carry DE(xD1) in Chinese studies. They could carry hg D2 or its direct predecessor.

As for hg D3, I bet that it and/or its direct predecessor will be found to the south and southeast of Xizang. Samples on Tibeto-Burmans there indicate that such a scenario is likely: the percentages of DE(xD1) are often comparable to those in Tibetans. However, that could also be a mere result of the Tibeto-Burmese movement into the south. Yet, I'm relatively confident that the mountaneous regions of today's Yunnan preserved some rare versions of y hg D which would support a migration from the south to former Kham into today's Xizang.

Hg D seems to be sparsest in the centre and in the southeast. But we can assume that this region was formerly inhabited by Hmong-Mien peoples among whom hg D1 was found. So one could wonder whether hgs D1 and D2 or D1 and D3 are closer to each other.

Quote:
 
In a side note: why do you use the Chinese name for Tibet (in Tibetan is "Bod")?. I wonder why you, that so much has complained about ethnical identity being erased by Chinese cultural centralization, now prefer to use ill-known Chinese nationalistic terms instead of the international one.


By avoiding the word "Tibet" I indirectly criticise Chinese politics. After all, the Tibet myth is partly a result of Chinese policy, too. Moreover, current tibetisation is actually a process initiated by the Chinese government. Before the Chinese rule the Tibetan cultural sphere (in its broadest sense) was by far less Tibetan than it is today. Today even the Moso people become more and more Tibetan. "Tibet" is nothing else but an inofficial cultural antipole to Beijing in the heads of many non-Chinese. By allowing Tibet to exist, one would only create two culturally centralistic governments (one Tibetan and one Mandarin) instead of one (Mandarin).

Xizang is a short word for "Ngari+Ü+Zang+western Kham".
http://en.wikipedia.org/wiki/%C3%9C-Tsang

Its territory does not include Amdo (aka "Great Tibet" in contrast to "Lesser Tibet", which is AFAIK Zang or Ü plus Zang; accordingly Amdopa are "Great Tibetans" and the Yarlung peasants "Lesser Tibetans") and eastern Kham, which are ethnically very heterogenous.
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Maju
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sorgina
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Ok. Thanks, Black Man. Your explanations and hypothesis would give a more plausible scenario for the interconnections between D sungroups. I was quite surprised nothing (but D1) had been found between Tibet and Japan, really. But it seems it's not the case in the end.
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black man
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ren
Apr 6 2007, 02:19 PM
It is possible that D1 and D3, and D* were the orginal lineages. In Tibetans, very curly hair is not unusual, and this might have something to do with D carriers. The archaeological context is that of a North Asian one, so it seems people moved into Tibet from NW China proper, and such techno-complexes seem to be ultimately derived from Central Asia, so it is possible that D came via Central Asia and was subsequently lost there, just as D in the Andamans came via South Asia but was subsequently lost in South Asia. That would make the origination of D to be before Central and South Asia, in SW Asia perhaps but was subsequently lost there.

I had originally thought D was of a southern origin based on D* in the Andamans and some popular theories about the Ainu and Jomon, but since the archaeology does not give evidence to this, it's possible that D came into ASia in atleast 2 separate routes, which is very interesting.

ren, what do know about Karl Jettmar's theory that Sino-Tibetan people from the Ordos or so moved to the Altai? Was it meanwhile refuted? (If not, such people could have added the y-chromosomes paragroup D[xD1,D2,D3] to the Altaian gene pool, which was reported by Hammer et al. in 2006.) I ask because I'm not so familiar with archaeological literature.
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Maju
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sorgina
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Excuse my ignorance if what I say is too far fetched but... couldn't the Andamanian D lineages have arrived via Burma (Myanmar). After all Andaman islands are just south of this country and the Irawady has been mentioned as one of the natural accesses to Tibet (and to China). Otherwise, AFAIK, Andaman's D is isolated in Southern Asia...
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Ibra
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We can’t ignore the mtDNA of the Andaman Islanders since a D migration to there likely involved M31a, and couldn’t have occurred more than 30,000 years ago. The LGM when sea levels were low has been suggested.

Quote:
 
This inter-regional connection is significant because it demonstrates a shared maternal gene-pool approximately half the age of haplogroup M31 itself. Assuming an age for haplogroup M of around 60 k years[48] the six coding region mutations preceding the splitting of M31a would centre this date around 30 kya. This is close to LGM low sea levels (20–25 kya), which may be significant in terms of access to the archipelago from the mainland. Without comprehensive data from Myanmar it is not possible to identify whether the Andaman M31a1 arrived from India or if the Indian M31a2 came from South-East Asia. But either scenario casts serious doubts on the concept that the Andaman Islands were settled at the time of the migrations out of Africa carrying the current Eurasian mtDNA diversity.
The additional insights into this seminal period of human pre-history afforded by this study suggest that more comprehensive sampling of contemporary populations is required and that tribal groups may be an important reservoir of genetic diversity vital to reconstructing human evolutionary history. In the context of the current study, Myanmar may prove vital to retracing population movements of the Late Pleistocene, including the settlement of the Andaman archipelago. It is also clear that there is an important role for museum collections in this process to recover crucial signals from populations that did not survive their encounter with modernity, or who have suffered considerable demographic reduction.


www.plosone.org/article/fetchArticle.action?articleURI=info:doi/10.1371/journal.pone.0000081
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ren
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Maju
Apr 7 2007, 10:26 PM
I was quite surprised nothing (but D1) had been found between Tibet and Japan, really. But it seems it's not the case in the end.

I think the D found in Korea is D2.

black man
Apr 7 2007, 11:45 PM
ren, what do know about Karl Jettmar's theory that Sino-Tibetan people from the Ordos or so moved to the Altai? Was it meanwhile refuted? (If not, such people could have added the y-chromosomes paragroup D[xD1,D2,D3] to the Altaian gene pool, which was reported by Hammer et al. in 2006.) I ask because I'm not so familiar with archaeological literature.

None what-so-ever, although any number of events in prehistory could've seen D move to the Altai from wherever. This horizone seems to have been connected in the late Pleistocene.

Maju
Apr 8 2007, 06:08 AM
Excuse my ignorance if what I say is too far fetched but... couldn't the Andamanian D lineages have arrived via Burma (Myanmar). After all Andaman islands are just south of this country and the Irawady has been mentioned as one of the natural accesses to Tibet (and to China). Otherwise, AFAIK, Andaman's D is isolated in Southern Asia...

You do have a point... There was never any depopulation in South Asia, so it's harder to believe that D just disappeared there or never shows up in Oceania (including parts of SE Asia).

If it arrived from Central Asia, it's easier to explain why it disppeared from Central Asia or even SW Asia, since there was depopulation during desertification. Of course, there is also the problem of why it never spread radially if it came through Central Asia.

A test of just exactly what kind of D the Andamans have would help to elucidate everything.

-----------------------------------------------------------------------------------------------

It's possible that D carriers lived in eastern coastal China during the late-Pleistocene-early Holocene. The Upper Cave specimens have certain similarities to Jomo and Ainu, and were coastal hunter-gatherers, like the Jomon and Ainu.
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black man
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ren
Apr 8 2007, 03:14 PM
Maju
Apr 7 2007, 10:26 PM
I was quite surprised nothing (but D1) had been found between Tibet and Japan, really. But it seems it's not the case in the end.

I think the D found in Korea is D2.

"D1" was detected in one Japanese American by Paracchini et al. (2003) and once by Hammer et al. (2000). All in all, men in this hg might constitute less than one percent of the Japanese. But Nonaka et al. will maybe give more insight into the migration movements of hg D1 into Japan and Korea because their sample sizes are big and include STR data. Since the paper has "online early" status, one will only have to wait for it being published and then two years until its access will be for free.
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