Mishra Rahul Kumar, Singh Prajjval Pratap, Rai Niraj, Desai Shailesh, Pandey Pratik, Tiwary Sachin Kr, Tamang Rakesh, Suravajhala Prashanth, Shrivastava Pankaj, Thangaraj Kumarasamy, van Driem George, Chaubey Gyaneshwer
Department of Zoology, Cytogenetics Laboratory, Banaras Hindu University, Varanasi, India.
Birbal Sahni Institute of Palaeosciences, Lucknow, India.
Eur J Hum Genet. 2024 Dec 6. doi: 10.1038/s41431-024-01720-w.
The Nicobarese are the major tribal groups in the Nicobar district, situated south of the Andaman group of Islands. Linguistic phylogeny suggests that the linguistic ancestors of the Nicobarese settled the Nicobar archipelago in the early Holocene. So far, genetic research on them is low-resolution and restricted to the haploid DNA markers. Therefore, in the present analysis, we have used the high-resolution biparental (1554 published and 5 newly genotyped Nicobarese individuals) and uniparental genetic markers and looked at the genetic association of Nicobarese with the South and Southeast Asian populations. We report a common ancestral component shared among the Austroasiatic of South and Southeast Asia. Our analyses have suggested that the Nicobarese peoples retain this ancestral Austroasiatic predominant component in their genomes in the highest proportion. On the Southeast Asian mainland, the Htin Mal, who speak an Austroasiatic language of the Khmuic branch, represent a population that has preserved their ethnic distinctness from other groups over time and consequently shown the highest drift with the Nicobarese. The analysis based on haplotypes indicated a significant level of genomic segment sharing across linguistic groups, indicating an ancient broader distribution of Austroasiatic populations in Southeast Asia. Based on the temporal analyses of haploid DNA, it is suggested that the forebears of the Nicobarese people may have arrived on the Nicobar Islands in the last 5000 YBP. Therefore, among the modern populations, the Nicobarese peoples and the Htin Mal language community represent good genetic proxies for ancient Austroasiatics.
尼科巴人是位于安达曼群岛以南的尼科巴地区的主要部落群体。语言系统发育研究表明，尼科巴人的语言祖先在全新世早期就定居在了尼科巴群岛。到目前为止，对他们的基因研究分辨率较低，且仅限于单倍体DNA标记。因此，在本分析中，我们使用了高分辨率的双亲（1554个已发表和5个新基因分型的尼科巴人个体）和单亲遗传标记，并研究了尼科巴人与南亚和东南亚人群的基因关联。我们报告了南亚和东南亚南亚语系人群之间共享的一个共同祖先成分。我们的分析表明，尼科巴人在其基因组中保留这种祖先南亚语系主要成分的比例最高。在东南亚大陆，说孟高棉语族南亚语系语言的廷马尔人是一个随着时间推移保持了与其他群体不同种族特征的人群，因此与尼科巴人的基因漂变程度最高。基于单倍型的分析表明，不同语言群体之间存在显著水平的基因组片段共享，这表明南亚语系人群在东南亚曾有过更广泛的古代分布。基于对单倍体DNA的时间分析，有人提出尼科巴人的祖先可能在过去5000年里到达了尼科巴群岛。因此，在现代人群中，尼科巴人和廷马尔语族群体是古代南亚语系人群很好的基因代表。
