I’ve been meaning to link to the recent study in Nature, “Reconstructing Indian Population History” (subscription reqd.) all week, but have been too busy (note: a document full of supplementary information is freely available here, though you need to be able to understand the way they do statistical analysis to make sense of all the charts).
As this is genetics, one would expect some comments from Razib, and indeed, one is not disappointed: here are Razib Khan’s comments on the study (see also this follow up post, where Razib creates his own plots based on the study’s data). The study gives data that relates to quite a number of different things, but the takeaway points seem to be : (1) South Indian and North Indian populations are genetically fairly mixed, and are (1a) more closely related to each other than to any other genetic/ethnic group; (2) the “Ancestral South Indian” genetic type is projected to most closely resemble a nearly extinct tribe in the Andaman Islands, the Onge (which is not to say that the Onge are themselves the “origin” of the South Indian gene pool); and (3) caste groups in the same regions of India show surprisingly high genetic difference in some cases, suggesting that caste endogamy within individual regions is a rather ancient practice.
According to Razib at least, the biggest limitation of this study is the small sample size (in the low hundreds). It seems clear that all of the conclusions being drawn from this study would be on stronger ground if they could go back and multiply the number of samples by 10.
Finally, there is a good, not overly technical synopsis of the Nature study at the Times of India: here. The TOI focuses on point (1) more than the others:
`This paper rewrites history… there is no north-south divide,” Lalji Singh, former director of the Centre for Cellular and Molecular Biology (CCMB) and a co-author of the study, said at a press conference here on Thursday.
Senior CCMB scientist Kumarasamy Thangarajan said there was no truth to the Aryan-Dravidian theory as they came hundreds or thousands of years after the ancestral north and south Indians had settled in India.
It is probably a mistake to read too much into this study, or even to accept the co-author’s bald claim that “there is no North-South divide” (Razib points out that it’s not that there aren’t genetic differences between North and South Indians — there are — but they fall on a gradient, rather than a solid barrier). Still, the study might have implications for South Indian activists who articulate a separatist “Dravidian” agenda, as well as North Indian “Aryan Invasion” proponents, who fantasize that they are really European. The only people who are really genetically “pure” on the Indian subcontinent are, it appears, the Onge.


























I realize also that this article might make some readers a bit anxious and reflective. Please don’t reflect. I assure you that SM falls under the essential use category. 


















. This week’s edition of the journal Science 

post about Tamiflu
I hate paying so much at the pump but I am glad that the current gas shortage has stabbed a dagger into the heart of SUV sales. It also seems like every other day there is a news story about someone tinkering with their engines, or the battery array in their hybrids, to get more juice for the buck. Sometimes innovation still does take place in the trenches.
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