View Full Version : Polynesian Y-DNA Origin?

10-05-2021, 04:41 AM
I've been reading on Polynesian genetics and have found 3 articles than seem to contradict themselves when analyzing Y-DNA/mtDNA.

1st source: Polynesians derive their Y-DNA mostly from Taiwanese Austronesians and the rest from Melanesians

2nd source: Polynesians derive their Y-DNA mostly from Melanesians, then from Austronesians

3rd source: Polynesians derive their Y-DNA mostly from Eastern Indonesian Austronesians, and little to none from Taiwanese Austronesians and Melanesians

"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). We find that, while haplogroups C2a, S and K3-P79 suggest a Melanesian component in 23%-42% of the Samoan and Tongan Y chromosomes, the majority of the paternal Polynesian gene pool exhibits ties to East Asia." (from National Library of Medicine 2011 Source (https://www.academia.edu/9375468/Increased_Y_chromosome_resolution_of_haplogroup_O_ suggests_genetic_ties_between_the_Ami_aborigines_f rom_Taiwan_and_the_Polynesian_Islands_of_Samoa_and _Tonga?auto=download))
"Overall in Polynesia, the proportion of Melanesian haplogroups was 11-fold higher for Y chromosomes (65.8%) than for mtDNAs (6%), and of Asian haplogroups was more than 3-fold higher for mtDNAs (93.8%) than for Y chromosomes (28.3%)." (from Oxford Academic 2006 Source (https://academic.oup.com/mbe/article/23/11/2234/1333210))
"Surprisingly, nearly none of the Taiwanese Y haplotypes were found in Micronesia and Polynesia. Likewise, a Melanesian-specific haplotype was not found among the Polynesians. However, all of the Polynesian, Micronesian, and Taiwanese haplotypes are present in the extant Southeast Asian populations. Evidently, the Y-chromosome data do not lend support to either of the prevailing hypotheses. Rather, we postulate that Southeast Asia provided a genetic source for two independent migrations, one toward Taiwan and the other toward Polynesia through island Southeast Asia... The absence of H17 from Polynesian populations suggests that the contribution of Melanesian Y-chromosomal haplotypes to the Polynesian expansion is very low or negligible, in contrast to the higher proportion of Melanesian alleles seen at nuclear and mtDNA loci." (from PNAS 2000 Source (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC26928/))

Can anybody tell me which source you believe to be more credible/accurate?

10-05-2021, 04:43 AM
Additionally this other study comes to this conclusion:

"This raises the wider issue of the degree of male gene flow throughout Oceania. Mantel testing provides no support for the contention of a prior study that male gene flow might be higher than female gene flow throughout Oceania. The previous findings may have more to do with the different effective population sizes and mutation dynamics of the mitochondrial and autosomal loci studied than they do with their different patterns of inheritance. While we do not discount the possibility of higher male than female gene flow in Oceania, the degree of differentiation between Melanesian, Micronesian, and Polynesian Y chromosomes does not appear to have a distinct ancestry to those fit with the description that higher male gene flow throughout Oceanic populations results in an “entangled bank” of diversity (Lum et al. 1998).

In conclusion, this study, while not strongly supporting the hypothesis of rapid Austronesian expansion from Taiwan, is not necessarily incompatible with it. Biological and cultural origins can become uncoupled to varying degrees. Whereas the dominant model for the cultural evolution of Pacific peoples does not adequately explain the origins of the majority of Polynesian Y chromosomes, the populations may still retain a genetic signal of their cultural origins in a minority of their paternal lineages."

Source (https://www.genetics.org/content/genetics/160/1/289.full.pdf)