By Vinod Varshney
The caste system in India creates fresh bias and hostility today, especially in the election season, because more and more sectarian groups make demands for job reservation in government and educational institutions. But seen in the light of genetics, there is not much difference amongst its population. The difference exists in only one percent of their genes. With immense advances in science, it is now possible to trace the history of various population groups. Some recent studies point out that the caste system in India is not very old. Ancient literature does provide some evidence, and genetic studies endorse it.
No one can claim that one is purely a South Indian or North Indian. The genetic evidence based on Reich's 2009 study, which analysed 25 different Indian population groups, suggests that initially there were indeed two main strains—Ancestral North Indian (ANI) and Ancestral South Indian (ASI). The ANIs were related to Central Asians, Middle- Easterners, Caucasians and Europeans while ASIs were primarily from the subcontinent. They might have lived side by side for long but did not inter-marry. The genetic mixing through marriages started some 4,200 years ago and continued till about the first century AD.
The caste system, as it is practiced now, is more about restriction in marriage between diverse groups and perpetuating the divisions for the sake of securing privileges. But genetic studies reveal that marriages among diverse population groups were the norm in ancient India. This means no group can claim any genetic purity. No one can say he or she is a pure Brahmin or Vaisya etc. The trend of marital mixing continued until about 1900 years ago.
Genetic studies also show that there was no migration from west Eurasia to India during the time of the said massive admixture of populations between 4,200-1,900 years from now. The Rig-Veda, a collection of hymns nearly 3,500 years old which mentions chieftains with South Indian names, is literature-based proof of inter-marriage between ANIs and ASIs. Another study found that there was no shared ancestry between the ANIs and groups in west Eurasia within the past 12,500 years. It means West Eurasians might have come to India before that period only. People migrated in multiple waves.
Ancient literature provides evidence that the period between 2200 BC and the first century AD was marked by tremendous demographic and cultural exchanges among Indian population. The Indus Valley civilization shifted eastwards owing to vagaries of the monsoon. People who engaged in agriculture settled in small groups along the Ganges belt. It was they who gave rise to the Vedic culture. This seems to be the period when inter-marrying began in a big way.
If the new genetic information is put in the backdrop of ancient texts, one can say with some certainty that class distinctions (varnas—Brahmin, Kshatriya, Vaisya and Shudra) emerged in India 3,000 to 3,500 years ago, and profession-based caste divisions became strict and birth-based 1,900 years ago.
There is no evidence of genetic mixing prior to 4200 years from now. Population groups might have lived side by side but there is no sign of inter-mingling. Inter-marrying became common thereafter and continued up to 1900 years ago. Then suddenly it stopped. Why?
Manusmriti gave the caste systemManusmriti is dated between 200 BC and 100 AD which gave caste system in as much as it codifies professions and social conducts of people pursuing those professions, giving rise to strict social stratification. Prescription of social conduct meant many restrictions also. Originally these preferable conduct and restrictions were linked to one’s profession, but later became linked to birth. It became a tool of discrimination, oppression and exploitation. The Shudra were specially treated inhumanly.
A genetic study undertaken jointly by the Harvard Medical School and the Centre for Cellular and Molecular Biology in Hyderabad on 571 carefully selected individuals from 73 well-defined ethno-linguistic groups in South Asia (71 Indians and 2 Pakistanis), has revealed that inter-marrying stopped around 1900 years ago. This was the time the caste system started in India and put a bar on marrying outside one’s caste. That there was no caste system prior to 1900 years from now is also evident from the part of the Rig Veda that was written in an earlier period. No mention of castes there. There was plenty of social movement, meaning persons of one population group were marrying into those of other population groups. This explains the presence of a wide variety of genes in Indian population.
But by the time Manusmriti was written several centuries after Rig Veda, the trend of inter-marrying in diverse social groups had stopped. Within just a short period the caste system had got firm roots in society. This was shown on the basis of linguistic and literary proofs, as well as genetic studies. Four classes (varnas)—Brahmin, Kshatriya, Vaisya and Sudra-- find mention in the Rig Veda parts written later.
(Note: The article was first published in the Lokayat magazine: April, 2014)