Increased Y-chromosome resolution of haplogroup O suggests genetic ties between the Ami aborigines from Taiwan and the Polynesian Islands of Samoa and Tonga.
Mirabal S, Herrera KJ, Gayden T, Regueiro M, Underhill PA, Garcia-Bertrand RL, Herrera RJ.
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Abstract
The Austronesian expansion has left its fingerprint throughout two thirds of the circumference of the globe reaching the island of Madagascar in East Africa to the west and Easter Island, off the coast of Chile, to the east. To date, several theories exist to explain the current genetic distribution of Austronesian populations, with the "slow boat" model being the most widely accepted, though other conjectures (i.e., the "express train" and "entangled bank" hypotheses) have also been widely discussed. In the current study, 158 Y chromosomes from the Polynesian archipelagos of Samoa and Tonga were typed using high resolution binary markers and compared to populations across Mainland East Asia, Taiwan, Island Southeast Asia, Melanesia and Polynesia in order to establish their patrilineal genetic relationships. Y-STR haplotypes on the C2 (M38), C2a (M208), O1a (M119), O3 (M122) and O3a2 (P201) backgrounds were utilized in an attempt to identify the differing sources of the current Y-chromosomal haplogroups present throughout Polynesia (of Melanesian and/or Asian descent). Specifically, while haplogroups C2a, S and K3-P79 suggest a Melanesian component in 23%-42% of the Samoan and Tongan Y chromosomes, the prominence of sub-haplogroup O3a2c* (P164), which has previously been observed at only minimal levels in Mainland East Asians (2.0-4.5%), in both Polynesians (ranging from 19% in Manua to 54% in Tonga) and Ami aborigines from Taiwan (37%) provides, for the first time, evidence for a genetic connection between the Polynesian collections and the Ami.
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The Austronesian expansion has left its fingerprint throughout two thirds of the circumference of the globe reaching the island of Madagascar in East Africa to the west and Easter Island, off the coast of Chile, to the east. To date, several theories exist to explain the current genetic distribution of Austronesian populations, with the "slow boat" model being the most widely accepted, though other conjectures (i.e., the "express train" and "entangled bank" hypotheses) have also been widely discussed. In the current study, 158 Y chromosomes from the Polynesian archipelagos of Samoa and Tonga were typed using high resolution binary markers and compared to populations across Mainland East Asia, Taiwan, Island Southeast Asia, Melanesia and Polynesia in order to establish their patrilineal genetic relationships. Y-STR haplotypes on the C2 (M38), C2a (M208), O1a (M119), O3 (M122) and O3a2 (P201) backgrounds were utilized in an attempt to identify the differing sources of the current Y-chromosomal haplogroups present throughout Polynesia (of Melanesian and/or Asian descent). Specifically, while haplogroups C2a, S and K3-P79 suggest a Melanesian component in 23%-42% of the Samoan and Tongan Y chromosomes, the prominence of sub-haplogroup O3a2c* (P164), which has previously been observed at only minimal levels in Mainland East Asians (2.0-4.5%), in both Polynesians (ranging from 19% in Manua to 54% in Tonga) and Ami aborigines from Taiwan (37%) provides, for the first time, evidence for a genetic connection between the Polynesian collections and the Ami.
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3 comments:
"Increased Y-chromosome resolution of haplogroup O suggests genetic ties between the Ami aborigines from Taiwan and the Polynesian Islands of Samoa and Tonga".
Didn't we already know that? However it is interesting to know that Polynesian O3 is now shown to be the derived haplogroup O2a2c*, 'which has previously been observed at only minimal levels in Mainland East Asians (2.0-4.5%)'. However derived O3a2c , in the form of O3a2c1, is reasonably common in Sino-Tibetan speakers evidently but is not very common in Polynesia. My guess is that the Taiwanese O3a2c will eventually be shown to be a single haplogroup within O3a2c, a sort of O3a2c2.
"Didn't we already know that?"
My thoughts exactly.
"My thoughts exactly".
However I have noticed something very interesting if we are prepared to accept that Polynesian O3a2c is paraphyletic. We can be sure that O3a2c can have reached Tonga no more than about 3000 years ago, having entered the Pacific islands beyond the Northern Solomons perhaps some 2000 years earlier: 5000 years ago. That the movement from Taiwan to the Southern Solomons was rapid is shown by the virtual absence of O3 of any kind along the coast of New Guinea and in the Northern Solomons. So o3a2c expanded from Taiwan around 5-7000 years ago.
That raises the distinct probability that O3a2c's expansion as a whole may have been within the same time frame. O3a2c1's expansion must be more recent. Perhaps 4000 years ago. Haplogroup O3a2c1 spread everywhere in an arc across China from Tibet to Japan. Had O3a2c already entered Polynesia by the time that O3a2c1 expanded through China?
Even if Polynesian O3a2c turns out to be monophyletic it doesn't alter the dates too considerably. Can anyone seriously claim that O3's expansion has nothing to do with the progressive development of the Neolithic in the East?
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