Genetic affinities and adaptation of the South West coast populations of India:
Evolutionary event has not only transformed the genetic structure of human populations but also associated with social and cultural transformation. South Asian populations were formed as a result of such evolutionary events of migration and admixture of genetically and culturally distinct groups. Most of the genetic studies pointed to large-scale admixture event between Ancestral North Indian (ANI) and Ancestral South Indian (ASI) groups, also additional layers of recent admixture. In the present study we have analyzed 213 individuals inhabited in South West coast India with traditional warriors and feudal lord status and historically associated with recent migrations events and possible admixture with Indo-Scythians, Saka, Huns and Kushans, whose genetic links are still missing. Analysis of autosomal SNP markers suggests that these groups possibly derived their ancestry from some groups of North West India having additional Middle Eastern genetic component and also their separation history suggests very early separation from North West Indian and Gangetic plain Indo-Europeans during late bronze or Iron age, most probably following central India and Godavari basin to South West coast. Higher distribution of west Eurasian mitochondrial haplogroups also points to admixture through maternal lineage. Selection screen using genome wide genealogy approach revealed genetic signatures related to their long-term coastal food habits. Thus, our study suggests that the South West coastal groups with traditional warriors and feudal lords’ status are of a distinct lineage compared to Dravidian and Gangetic plain Indo-Europeans and are remnants of very early migrations from North West India following Godavari basin to Karnataka and Kerala.
If you do a west-to-east transect there is more “ANI” ancestry in the west of the subcontinent. This is true in the north, obviously (Punjabis to Bengalis), but less appreciated is that the same seems true in the peninsula south of the Vindhya Range. To some extend this is due to more steppe ancestry in groups like Nairs because of “gene flow” from Namboothiri Brahmins and such. But, that’s not all. As noted in this paper some of these western coastal groups clearly have an excess of “Middle Eastern” ancestry. That’s not surprising for the Jews of Cochin or even the Nasrani Christians. But what about Bunts and Nairs? There are two main ways you can explain this in my opinion:
1) A pre-steppe IVC and post-IVC era migration of “Iranian” peoples associated with the Ashmound culture has a significant impact that is most preserved in the western part of the peninsula
2) Later connections between West Asian (Arab and pre-Arab) people who were integrated into the local cultures over time (due to the matrilineal nature, at least originally, of some of these southwestern groups one can imagine how easy it would be to integrate sailors from other societies, or at least their offspring)
Just glanced over the paper and noticed a few things :
– The steppe_MLBA ancestry of every group in this paper in terms of AHG, Indus_Diaspora and Steppe_MLBA seems to be slightly inflated by 5%-6% compared to the estimates given in narasimhan et al using the same left pops. I didn’t find p-values for this model so that makes me wonder !
– Some of those sikh_jatt samples(same as one ones used in narasimhan which in turn are taken from an earlier study) have clearly something shady going on. In the PCA, while most of them are north-shifted(near pashtuns, kambojs etc) , some of them seem quite south shifted towards some non-dalit south indian castes. Those can’t be a part of natural variation in an endogamous caste found in only one state(punjab). On anthrogenica, I remember reading one post where they found that some of those samples were sharing high IBD segments were Haryana’s dalits. So, it seems that some of those sikh_jatt samples are either admixed with dalits or mislabelled dalits.
– Bunts, surprisingly, have 25% mtDNA H. This is quite a lot.
Hi – I don’t care about jat sikhs or such but wondering about what this paper means for ancestry of Nairs from Kerala. I’m a nair with r1a on paternal and u1a3 on maternal side. I’ve always personally noticed cultural similarities with bunts and even with kodava people from karnataka.
Is this paper’s suggestion that south west warrior groups all collectively descend from some common migration from the northwest plausible in your view Razib?
@razib
> A pre-steppe IVC and post-IVC era migration of “Iranian” peoples associated with the Ashmound culture
This is really interesting. I’ve long looked for references and clues about the origins of this culture, could you point to further reading?
Is this paper’s suggestion that south west warrior groups all collectively descend from some common migration from the northwest plausible in your view Razib?
yes. but i’ve looked at lots of nairs, there is a cline to namboothiri brahmins for the reasons you know…
Yes – we had polyandry and polygamy. The polygamy was only between nairs while the polyandry could also include namboodiris. In the end only your ancestry from mothers side mattered. Most nairs until the early 20th century wouldn’t even have known who their biological father was. You uncle on mothers side is the father figure for all intents and purposes. This is the tharavad system and was our way.
Btw for whatever it’s worth most namboodiris I’ve met have been quite short whereas this trait doesn’t appear to have been inherited by nairs. Anecdotal but I have noticed it.
My real questions I suppose are, does this paper imply that the r1a on the paternal side could have been there before the arrival or namboodiris? And, more importantly, what is the origin of the maternal u1a3 – would that have been Indus Valley as this paper implies some female mediated ancestry from the northwest.
As mentioned clarity on the maternal ancestry means more to us.
Thank you.
This is really interesting. I’ve long looked for references and clues about the origins of this culture, could you point to further reading?
all i know i know from bellwood
From the paper (Pg no. 8)
“For Nairs, we obtained a graph topology with best fit (likelihood score 2.94125), showing a pattern of admixture typical of ANI-ASI admixture from an ASI group similar to Palliyar and an ancient ghost population ANI formed by admixture between Indus population and Yamnaya like Steppe group (Fig S5a). In addition to this simple ANI-ASI admixture, Nairs also require another source group for Middle East ancestry from Bactria-Margiana-Archeological-Complex (BMAC).”
Isn’t BMAC more likely to be the source of the middle eastern ancestry?
Razib, can you do a IVCp|BMAC|Steppe_MLBA|AHG model qpAdm run on the groups mentioned in the paper?
The authors find it “surprising “that the Nairs have a high Namazga component, but then modelling with Namazga and steppe and onge gives good fits for many south asian groups…..there is no doubt that the major chunk of the steppe Nairs get is from nambuthiris….but was there a minute steppe admixture prior to sambandham with nambuthiris….and what is this about BMAC needed to get a better fit for Nairs????….do the authors mean that Nairs had gene flow from the Oxus culture??….the BMAC people from my knowledge had genetic contributions from Anatolian farmers, neolithic Iranians and a small input from the West Siberian Hunter Gatherers….some of the Nair DNA Kits i have have a siberian component( 1-3%)….and on G25 runs, …Kazakhstan Botai shows up, ….so many questions!!!)))