Biology subjects

Tamang, R.

Publications and source records attributed to Tamang, R..

3 recordsLinked to original sources

bioRxiv2026

Holocene North Asian gene flow and cryptic substructure in the genome history of Nilgiri tribes

The Nilgiri Hills of the Western Ghats harbour several historically isolated tribal populations whose genomic history remains incompletely resolved. Here, we present a comprehensive analysis of whole genome and complete mitochondrial data from three major Nilgiri groups i.,e, Toda, Kota, and Kurumba, in the context of a broad Eurasian reference panel. Autosomal analyses reveal previously unrecognised fine scale substructure, with both Kota and Kurumba resolving into two genetically distinct clusters (Kota1/Kota2 and Kurumba1/Kurumba2). Principal component, ADMIXTURE, and fineSTRUCTURE analyses identify Toda as the most genetically drifted Nilgiri group, whereas Kota2 exhibits elevated Austroasiatic related ancestry. qpWave analysis indicates that the five genetic clusters require at least three independent ancestry streams, while qpAdm further differentiates the groups based on Onge, Indus Periphery, and Western SteppeMLBA related ancestry. Toda shows the highest Indus Periphery related and lowest Onge related ancestry among the Nilgiri groups. A distinctive ancestry component shared by Kurumba2, Kota1, Gaud and the Sri Lankan Vedda suggests deeper ancestral connections across the southern Indian Ocean region. Mitochondrial genomes reveal strong founder effects and lineage specific patterns, including R5a2b in Toda, M3a1 in Kota, and multiple M subclades together with the rare C4a2c1 lineage in Kurumba. Notably, C4a2c1, previously understudied in South India, shows phylogenetic and ancient DNA continuity with North Asian and Siberian lineages. Bayesian dating suggests its arrival in the Indian subcontinent during the early mid Holocene (~7 ka), followed by local diversification after ~5 ka. Together, these findings reveal a complex history of long range Holocene maternal gene flow and subsequent isolation driven differentiation, providing new insights into the genomic history of South Indian tribal populations.

evolutionary biology↗

bioRxiv2024

Northeast India: Genetic Inconsistency across Ethnicity and Geography

The genetic landscape of South Asia is intriguing. In a vast geographical region like India, mostly genes follow geography, whereas in a smaller geographical region e.g., Nepal, the genetic landscape is more akin to languages. Moreover, in neighboring regions like East and Southeast Asia, language is the major denominator of the genes. However, these are not just the two alternatives, in many geographical pockets, ethnicity plays a stronger role than either of these. Being a crossroads of South and Southeast Asia, the Himalayan region is mostly populated by people speaking the Trans-Himalayan language. Archaeological and anthropological studies suggest migration and cultural diffusion in this region with the Tibetan plateau in the North. To understand this complex pattern, we have performed a fine-grained genetic analysis of the major Mizo population and its various clans living in the Himalayan geography. We have investigated 110 individuals belonging to seven different clans of Mizo people for a hundred thousand autosomal markers. We have used various statistical methods and tested the role of ethnicity and geography in shaping the genetic landscape of the Himalayan region. In contrast to the East and Southeast Asian genetic landscape, our results suggested that the fine-scaled genetic structure of Northeast India is much more complex and a mixture of interplay between languages, ethnicity, and geography. Allelic frequency-based analyses indicated that a novel Trans-Himalayan ancestry unite all the populations of this region.

evolutionary biology↗

bioRxiv2017

Like Sugar in Milk: Reconstructing the genetic history of the Parsi population

BackgroundThe Parsis, one of the smallest religious community in the world, reside in South Asia. Previous genetic studies on them, although based on low resolution markers, reported both Iranian and Indian ancestries. To understand the population structure and demographic history of this group in more detail, we analyzed Indian and Pakistani Parsi populations using high-resolution autosomal and uniparental (Y-chromosomal and mitochondrial DNA) markers. Additionally, we also assayed 108 mitochondrial DNA markers among 21 ancient Parsi DNA samples excavated from Sanjan, in present day Gujarat, the place of their original settlement in India.\n\nResultsOur extensive analyses indicated that among present-day populations, the Parsis are genetically closest to Middle Eastern (Iranian and the Caucasus) populations rather than their South Asian neighbors. They also share the highest number of haplotypes with present-day Iranians and we estimate that the admixture of the Parsis with Indian populations occurred [~]1,200 years ago. Enriched homozygosity in the Parsi reflects their recent isolation and inbreeding. We also observed 48% South-Asian-specific mitochondrial lineages among the ancient samples, which might have resulted from the assimilation of local females during the initial settlement.\n\nConclusionsWe show that the Parsis are genetically closest to the Neolithic Iranians, followed by present-day Middle Eastern populations rather than those in South Asia and provide evidence of sex-specific admixture from South Asians to the Parsis. Our results are consistent with the historically-recorded migration of the Parsi populations to South Asia in the 7thcentury and in agreement with their assimilation into the Indian sub-continents population and cultural milieu \"like sugar in milk\". Moreover, in a wider context our results suggest a major demographic transition in West Asia due to Islamic-conquest.

evolutionary biology↗