Genetic affinities of Indian caste and tribal groups
A new paper in BMC Genetics examines the origins of Indian population groups. There have been other recent studies on the same topic.
BMC Genet. 2006 Aug 7;7(1):42
Genetic affinities among the lower castes and tribal groups of India: Inference from Y chromosome and mitochondrial DNA.
Thanseem I, Thangaraj K, Chaubey G, Singh VK, Bhaskar LV, Reddy MB, Reddy AG, Singh L.
ABSTRACT: BACKGROUND: India is a country with enormous social and cultural diversity due to its positioning on the crossroads of many historic and pre-historic human migrations. The hierarchical caste system in the Hindu society dominates the social structure of the Indian populations. The origin of the caste system in India is a matter of debate with many linguists and anthropologists suggesting that it began with the arrival of Indo-European speakers from Central Asia about 3500 years ago. Previous genetic studies based on Indian populations failed to achieve a consensus in this regard. We analysed the Y-chromosome and mitochondrial DNA of three tribal populations of southern India, compared the results with available data from the Indian subcontinent and tried to reconstruct the evolutionary history of Indian caste and tribal populations. RESULTS: No significant difference was observed in the mitochondrial DNA between Indian tribal and caste populations, except for the presence of a higher frequency of west Eurasian-specific haplogroups in the higher castes, mostly in the north western part of India. On the other hand, the study of the Indian Y lineages revealed distinct distribution patterns among caste and tribal populations. The paternal lineages of Indian lower castes showed significantly closer affinity to the tribal populations than to the upper castes. The frequencies of deep-rooted Y haplogroups such as M89, M52, and M95 were higher in the lower castes and tribes, compared to the upper castes. CONCLUSIONS: The present study suggests that the vast majority (>98%) of the Indian maternal gene pool, consisting of Indio-European and Dravidian speakers, is genetically more or less uniform. Invasions after the late Pleistocene settlement might have been mostly male-mediated. However, Y-SNP data provides compelling genetic evidence for a tribal origin of the lower caste populations in the subcontinent. Lower caste groups might have originated with the hierarchical divisions that arose within the tribal groups with the spread of Neolithic agriculturalists, much earlier than the arrival of Aryan speakers. The Indo-Europeans established themselves as upper castes among this already developed caste-like class structure within the tribes.
This came from:
Well this is not anything I did not expect, you can look at the Indian population, if you exclude Goa, the most (European) looking Indians come from the North West, an area that has been invaded by Greeks, Persians, and possibly sometype of proto-Europeans from Eastern Europe…so and it also does not suprise me that most o the invaders were likely men and militarily advanced. Traditionally, thorughout history, this was the norm, the men married local women and either imposed their culture on the natives or adopted the native culture, so most of the genetic variation in on the male side. It is not clear who founded Hinduism, was it indigenous (and abosrbed some outside relgiious characteristics) or was it primarily brought by invaders to the region. Maybe we will never know.
It does seem the majority of the population in the past was Dravidian, and it also seems (from other studies) they migrated through Iran at some time (as their are still Dravidian speakers there and in Pakistan)…I have also read that through genetic testing, it has been found that in South India, their are still very small populations who are related strongly to Aboriginees in Australia and groups in the South Pacific…likely the route people took to get to South East Asia and Austrlia (migrating along the coast, some stayed on and were absorbed by Dravidian populations much later).