The upper caste Indian male population is genetically closer to Europeans than the lower castes, which are more “Asian”, according to a potentially controversial new study being published in the forthcoming issue of the journal Human Genome. The authors of the study say their findings support historical data indicating that West Eurasians migrating into India during the last 10,000 years were mostly male. An analysis of the genetic material also shows that the “ancestors of Indian men and women came from different parts of the world,” say Michael Bamstad of the University of Utah , who led the research group.
The researchers say this difference in gender and genetic make up may also hold the key to the origin of the caste system. The migrating or invading male population left descendants in the higher than lower castes and may have even devised the caste system. Bamshad said in an interview with this correspondent on Thursday.
Bamshad’s study showed that each caste’s mitochondrial DNA, which is derived from the mother only, has a greater similarity to Asians than to Europeans, but the upper castes show less similarity than do the lower castes.
Conversely, Y-chromosome data, derived from the father only, show each caste more similar to Europeans, with the upper castes being most similar, probably because more similar, probably because more Eurasian males migrated to India than did Eurasian females.
Such a finding could also imply that the women of the sub-continent are more Indian than are men. To “increase the power of the study,” Bamstad and his associates also examined 40 additional genes that are inherited form the father and the mother. All of these data strongly supported the conclusion that upper castes have a higher genetic similarity to Europeans than do lower castes, the study says.
“These are potentially controversial results,” Bamstad said, “But we are able to demonstrate unequivocally that the upper castes are more similar to Europeans than lower castes, and that women are more mobile –mostly upwardly—in the caste system.”
The study in fact says the genetic distance is closed between Europeans and Brahmins (0.10) followed by Kshatriyas (0.12) and Vaishyas (0.16).
“Assuming that contemporary Europeans reflect West Eurasian affinities these data indicate that the amount of West Eurasian mixture with Indian population may have been proportionate to caste rank,” the study says.
Bamshad’s collaborators in the study include researchers from the Andhra University, University of Madras and the Anthropological Survey of India . The group has done work in this area before. In a previously published paper in Nature magazine, Bamshad’s team said each Indian caste had developed a distinctive genetic profile, particularly among men, and more so when there was little intermarriage. But the women’s genes suggested greater social mobility.
The discovery suggests that women on occasion marry men from higher castes producing children that have their husband’s social rank, the researchers said, claiming the “stratification of the Hindu caste system is driven by women.”