Monday, April 07, 2008

Absurdities of Caste Genetic Studies - Notes

Another absurdity that I come across routinely in the caste genetic studies is arbitrary distribution of upper/middle and lower caste categories. This random assignment of caste position adversely influences the haplogroup distribution and messes up our effort to understand the migratory patterns of various clans.

Consider the paper, "High Resolution Phylogeographic Map of Y-Chromosomes
Reveal the Genetic Signatures of Pleistocene Origin of Indian Populations", by Trivedi et al.(2007). I can summarize their method of caste categorization thus;

1. The states where Brahmins are not part of the samples, upper caste position is taken by middle castes.
eg. Kerala
-> Namboodiri Brahmins are not part of the study.

2. The states where Dalits are not part of the samples, lower caste position is taken by some of the middle castes.
eg. Andhra Pradesh
-> Mala and Madiga groups are not part of the study.

The situation is similar for Karnataka samples where Gowdas(equal to Nair/Reddy/Kammas who occupy middle caste position in the social scale) have been grouped under lower castes. Ironically, if we check Tamil Nadu samples Gowndar (Tamil equivalent of Kannada Gowda) are part of upper castes (as Tamil Brahmins are not part of the

With such a strange assignment of caste groups authors go on and determine distribution of various haplogroups in the pooled upper/middle and lower caste groups!

Now let's see about the consistency between two studies. In Thanseem et al.(2006) study, Kammas are part of upper castes and in Trivedi et al.(2007) study they are part of lower castes! Are any of the Indian genetic studies peer reviewed?

Once in a while Indian geneticists working with European counter parts take it upon themselves to teach a thing or two about Indian castes to their peers. So, we have Choubey et al.(2006) study with an information box on Scheduled castes and Tribes;

Scheduled Castes and Scheduled Tribes are communities in India that are given a special status by the Constitution of India. Scheduled castes were considered as ‘Sudra’ in the classical ‘Chaturvarna’ caste system while Scheduled tribes were considered ‘outcastes’ and were not a part of the Indian caste system.

There is so much cynicism in that para that I dread to touch it. I must only point out that tribes as long as they didn't join the mainstream their ritual purity was higher than that of communities that are classified now as Scheduled castes (Probably Choubey needs to read Ambedkar's essays first).


Maju said...

That's pretty interesting: I always got quite confused by studies of Indian genetics along caste lines, specially when the info of castes is only given away as a processed output.

So we can basically dsregard their conclussions. I'm too often criticising some of the conclusions of genetic studies and most people instead seem to take them as intrinsecally valid. The data (clear data prefereably) is more important actually.

Manjunat said...

Trivedi et al. is still a good study. If they publish data for individual castes instead of combined categories(as they have done now) then that would be helpful in datamining.

Maju said...

Wow! 6300 Google hits for scholarly papers by some Trivedi (in the team), mentioning India and genetics. A direct link could be helpful, really.

But you are right: if at least they would abide by the actual varna divisions and not generalize to vague arbitrary fluctuating categories like "high" and "low" castes, that would be more helpful (and less pretentious).

Anonymous said...

Nairs are not the middle order class indeed almost all the royals and Landowners comes from them and the Keraliate Brahmans are their close related cousin because of the maternal system of Nairs.

Manjax Wafer said...

Keraliate Brahmans are their close related cousin because of the maternal system of Nairs

Can that make Nairs a proxy for Namboodiris?

I suppose the present day population composition of Nair is 15% and Namboodiri - 1% (approximately).

Typically, South Indian Brahmins make up 3% of the native population in other regions.

Considering exclusive Sambandham between younger sons of Namboodiris and Nair women, let's say 2/3rd of Namboodiri numbers have become part of Nairs.

That is 2/15th of Nairs (~13%) have direct Namboodiri ancestry.

That still doesn't make general population of Nairs a proxy for Namboodiri population.

Therefore, the assignment of 'upper caste' to Nairs in the study is invalid.

Aaryan Gowda said...

Vokkaliga(Gowda) is the most forward caste in entire south india....dont compare gowdas with other castes plz...