Comments on: South Asians too are sons of the farmers?

By: Joe

Joe — Mon, 20 Dec 2010 17:47:32 +0000

I’m with ss. The north kannada component is still mysterious. Any speculation?

By: manju

manju — Mon, 20 Dec 2010 05:27:37 +0000

Dravidian Dalits (Mala, Madiga, Pallar etc…) have reasonably high percentage of R1a1 (>20%). However, Dravidian middle castes (Kamma, Velama, Okkaliga, Goundar, Vellala, Reddy) exhibit relatively low levels of R1a1. And in between, middle and lower, artisans (weavers) and herders may also exhibit high levels of R1a1. Based on the caste names and cultural motifs, artisans and herders definitely have north (or east India … UP + Bihar .. Magadha region) Indian admixture. I assume that would be the case with Dalits too. The name Mala, Mallar (Pallar) does have resonance in North India. Madigas are traditional shoemakers. And shoemakers make up the bulk of North Indian Dalits.

Interesting would be Dravidian middle castes across South India and Dravidian tribal (with lower R1a1) comparison. Some caution has to be taken for Nayars of Kerala and Bunts of coastal Karnataka.

By: ss

ss — Mon, 20 Dec 2010 03:45:55 +0000

The labels seem to be ok. Based on purely geographical grounds, I would have expected the amount of North Kannadiga component to be similar to that in AP or Tamil lower caste or to that in AP or Tamil Bramhins. Does this indicate that this is a component which brings about a finer distinction between Kannadiga populations on the one hand and Tamil and Telugu populations on the other?

However. based on current linguistic theories (http://en.wikipedia.org/wiki/Dravidian_languages) I would expect that Tamil and Kanndiga to be similar and to be distinguishable from Telugus. But the admixture data seems to suggest otherwise…

By: Razib Khan

Razib Khan — Sun, 19 Dec 2010 19:10:54 +0000

my labels are probably misleading. see dieneke’s original post.

By: Joe

Joe — Sun, 19 Dec 2010 19:00:39 +0000

I’m surprised how much generic indian and how little dravidian that tamil lower castes have. I’d expect them to be more like kannada. Likewise for the madiga. Any ideas on why this is?

By: Paul Kekai Manansala

Paul Kekai Manansala — Sat, 18 Dec 2010 20:11:10 +0000

Sad to see these bulk non-haplogroup SNPs used to restart discussion on genetic “race.”

The driving force behind this hapmap research is the race-based medicine industry.

By: Razib Khan

Razib Khan — Sat, 18 Dec 2010 08:56:26 +0000

minor note: just realized that my ratio of east asian:southeast asian is probably too balanced to be purely munda.

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Sat, 18 Dec 2010 03:28:53 +0000

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By: Razib Khan

Razib Khan — Sat, 18 Dec 2010 00:04:37 +0000

There are several plausible sources for the West Eurasian component collectively identified as Ancesteral North Indian: (1) the original Out of Africa population of the area, (2) Harappan (aka Indus Rivery Valley) colonization from Mesopotamia or Iran (probably in a single rather cohesive wave), (3) Indo-Aryan influence, and (4) subsequent Western invaders e.g. Greek and Muslim and English. The last possible source, while plausible, seems unlikely in light of the evidence, to have had much of a population genetic impact.

#1 is not plausible. ANI is not that far from west asian and europeans Fst wise. ASI is. keeping ANI and ASI so distinctive but geographically close is totally implausible. the only way this could work is if ANI is ancestral to west asian and european groups, which is implausible for other reasons.

#2 is not as implausible, but it is unlikely to be the whole story because tribal dravidians in south india have a substantial fraction of ANI. it was always a problem also that r1a1a was at non-trivial frequencies among these same groups too. the indo-aryans may have had a non-trivial impact, but i don’t think they can explain the preponderance of ANI.

By: ohwilleke

ohwilleke — Fri, 17 Dec 2010 23:46:08 +0000

But, it is hard to distinguish the first, second and third scenarios, and is particularly hard to parse out the Harappan from the Indo-Aryan sources, as an ancesterally Harappan population would have been one of the first societies to be assimilated into the Indo-Aryan society and that group of people became a major source point for subsequent Indo-Aryan expansion in all directions of the Indo-Iranian world. (The first component may be captured better by the ASI component than the ANI component.)

An ability to genetically parse Out of Africa v. Harappan v. Indo-European contributions to ANI would be desirable, if it could be achieved, because it would tell us more about who each of these ancient populations really were, and also because it would help resolve our understanding of the process by which Eurasians became genetically distinct from Africans.

Sometime between the formation of an Out of Africa founder population (somewhere) and the arrival of people in Australia ca. 50,000 years ago, a whole lot of mutations across the genome appear that have very wide geographic dispersal even for genetric patterns many mutations removed from Africa. Pylogenetically, we can determine which versions are more ancient and which are more recent. But, if for example, a particular pattern of genes is common in Northern Pakistan, the multiple layers that we know exist in the population make it hard in isolation to determine when and from where that group of genes entered the mix.