title: Molecular insights into the origins of the Shompen, a declining population of the Nicobar archipelago.
abstract: The Shompen, one of the most isolated and poorly understood contemporary hunter-gatherer populations, inhabit Great Nicobar Island, the southernmost island of the Nicobar archipelago. Morphological imprints in the Shompen were interpreted to favour a mixed Indo-Chinese, Malay, Negrito and Dravidian origin. Analyses of the mitochondrial, Y-chromosomal and autosomal gene pool of contemporary Shompen have revealed low diversity, illustrating a founder effect in the island population. Mitochondrial sequence analyses revealed the presence of two haplogroups of R lineage: B5a, and a newly defined clade, R12. Y-chromosomal analyses demonstrated the occurrence of a single lineage found predominantly in Austro-Asiatic speakers across Asia. With the different types of genetic markers analysed, the Shompen exhibit varying levels of genetic relatedness with the Nicobarese, and Austro-Asiatic speakers of mainland India and Southeast Asia. These genetic analyses provide evidence that the Shompen, an offshoot of the Nicobarese, are descendants of Mesolithic hunter-gatherers of Southeast Asian origin, deriving from at least two source populations.
authors.affiliation: National DNA Analysis Centre, Central Forensic Science Laboratory, 30 Gorachand Road, Kolkata, 700014, West Bengal, India.
authors.forename: Rajni
authors.initials: R
authors.lastname: Trivedi
authors.affiliation: National DNA Analysis Centre, Central Forensic Science Laboratory, 30 Gorachand Road, Kolkata, 700014, West Bengal, India.
authors.forename: T
authors.initials: T
authors.lastname: Sitalaximi
authors.affiliation: National DNA Analysis Centre, Central Forensic Science Laboratory, 30 Gorachand Road, Kolkata, 700014, West Bengal, India.
authors.forename: Jheelam
authors.initials: J
authors.lastname: Banerjee
authors.affiliation: National DNA Analysis Centre, Central Forensic Science Laboratory, 30 Gorachand Road, Kolkata, 700014, West Bengal, India.
authors.forename: Anamika
authors.initials: A
authors.lastname: Singh
authors.affiliation: Andaman Adim Janjati Vikas Samiti, Government of India, Port Blair, India.
authors.forename: P K
authors.initials: PK
authors.lastname: Sircar
authors.affiliation: National DNA Analysis Centre, Central Forensic Science Laboratory, 30 Gorachand Road, Kolkata, 700014, West Bengal, India. nibindia@vsnl.net.
authors.forename: V K
authors.initials: VK
authors.lastname: Kashyap
mesh_terms: D041322:Chromosomes, Human, Y; D004272:DNA, Mitochondrial / Q000235:genetics; D018703:Founder Effect; D005828:Genetics, Population; D007194:India
chemical_list: D004272:DNA, Mitochondrial