The Autochthonous Origin and a Tribal Link of Indian Brahmins: Evaluation Through Molecular Genetic Markers. S. Sharma1,2, E. Rai1,2, S. Singh1,2, P.R. Sharma1,3, A.K. Bhat1, K. Darvishi1, A.J.S. Bhanwer2, P.K. Tiwari3, R.N.K. Bamezai1 1) NCAHG, SLS, JNU, New delhi; 2) Department of Human Genetics, GNDU, Amritsar; 3) Centre for Genomics, SOS zoology, JU,Gwalior.

   The co-existence and associated genetic evidences for the major rival models: i) recent Central Asian introduction of Indian caste system, ii) rank related west Eurasian admixture, iii) South Asian origin for Indian caste communities, and iv) late Pleistocene heritage of tribal and caste populations, leave the question of the origin of caste system in India hazy and obscure. To resolve the issue, we screened 621 Y-chromosomes (of Brahmins, occupying upper most caste position and Dalits and Tribals with the lower most positions in the Indian caste hierarchical system) with fifty-five Y-chromosomal binary markers and Y-microsatellite markers and compiled a data set of 2809 Y-chromosomes (681 Brahmins, 2128 Tribals and Dalits) for conclusions. Overall, no consistent difference was observed in Y-haplogroups distribution between Brahmins, Dalits and Tribals, except for some differences confined to a given geographical region. A peculiar observation of highest frequency (upto 72.22%) of Y-haplogroups R1a1* in Brahmins, hinted at its presence as a founder lineage for this caste group. The widespread distribution and high frequency across Eurasia and Central Asia of R1a1* as well as scanty representation of its ancestral (R*, R1* and R1a*) and derived lineages across the region has kept the origin of this haplogroup unresolved. The analyses of a pooled dataset of 530 Indians, 224 Pakistanis and 276 Central Asians and Eurasians, bearing R1a1* haplogroup resolved the controversy of origin of R1a1*. The conclusion was drawn on the basis of: i) presence of this haplogroup in many of the tribal populations such as, Saharia (present study) and Chenchu tribe in high frequency, ii) the highest ever reported presence of R1a* (ancestral haplogroup of R1a1*) in Kashmiri Pandits (Brahmins) and Saharia tribe, and iii) associated averaged phylogenetic ages of R1a* (~18,478 years) and R1a1* (~13,768 years) in India. The study supported the autochthonous origin of R1a1 lineage and a tribal link to Indian Brahmins.