First, thanks to Zack for the opportunity to blog here. More importantly, thanks to Zack for the Harappa Ancestry Project! I've learned a lot from him in terms of the optimal way to go about "genome blogging," and have been able to benefit from his experiences in my own African Ancestry Project. It's really great that in 2011 we don't have to wait for academic researchers to explore the topics which interest us at the intersection of genetics and history.
Prior to being interested in South Asian genetics on such a fine-grained level I had read works such as Nicholas B. Dirks' Castes of Mind. To give you a sense of Dirks' argument, here's the summary from Library Journal:
Is India's caste system the remnant of ancient India's social practices or the result of the historical relationship between India and British colonial rule? Dirks (history and anthropology, Columbia Univ.) elects to support the latter view. Adhering to the school of Orientalist thought promulgated by Edward Said and Bernard Cohn, Dirks argues that British colonial control of India for 200 years pivoted on its manipulation of the caste system. He hypothesizes that caste was used to organize India's diverse social groups for the benefit of British control. His thesis embraces substantial and powerfully argued evidence. It suffers, however, from its restricted focus to mainly southern India and its near polemic and obsessive assertions. Authors with differing views on India's ethnology suffer near-peremptory dismissal....
One of the inferences which people draw from this model, perhaps unfairly, is that the endogamy and biological separation of caste groups is relatively new, and that genetic variation is likely to be arbitrarily distributed across caste groups. The most extreme interpretations almost seem to turn the British into the culture-creators of all that is Indian. In any case, genetics can obviously test the power of this thesis in relation to ancestry.
First up, below I have taken all the HAP samples where N >= 2. I've done some semantic shifting, so that "Tamil Iyer" becomes "Tamil Brahmin." I know that some of you have more information about the samples than is listed in Zack's spreadsheet, but I've been conservative. I will also use the word "community" sometimes instead of "caste" in future posts, because I don't know what the proper word for Syrian Christians or Bihari Muslims would be. But really same difference to me. I want to focus on groups with caste/religious labels intersected with a specific region here. The bar plot below is not going to be a surprise, and you see the clusters in Zack's dendograms, but I thought it would still be useful.
Caste is not genetically arbitrary. To me this strongly falsifies any contention that the endogamous units which we know as castes (or jatis) derive predominantly from the past 200 to 300 years. Tamil Brahmins number in the millions, so it does not seem that they plausible that could have expanded so rapidly from a very small homogeneous founder group two to three centuries ago. Rather, their origins are almost certainly more ancient. Some of the results are also not that surprising. Northwest Indians have the genetic profile you'd expect in comparison to other groups. The Bengali Brahmins consistently have more of an "East Asian" trace than other Brahmin groups, while Tamil Brahmins seem elevated in the "SW Asian" fraction in relation to other Brahmins. Both of these trends I think illustrate the likelihood of some admixture with location populations.
Now let's look within regions a bit. I'll divide South Asia into four quadrants. The classification will be self evident from the bar plots.
I'm the third to last Bengali, while the last two are are my parents. My parents are not related, and from opposite ends of Comilla east of the Padma. My mother is the last bar plot, and from a family with attested Middle Eastern ancestry (non-South Asian focused ADMIXTURE runs tend to bring the small, but non-trivial, element out more clearly). I believe that that is what is elevating her "SW Asian" fraction. It is notable that the two other individuals from eastern India who show this balance between "SW Asian" and "European" are also of Muslim background. I doubt that that is coincidental. Though South Asian Muslims are overwhelmingly indigenous, they do seem to have some outside admixture since the arrival of Arabs, Persians, and Turks, to the subcontinent. The most obvious marker of this to me isn't the elevation of "SW Asian," but the common presence of African ancestry among Pakistani Muslims. This certainly is due to the arrival of Africans and people of part African origin in the retinues of Indo-Islamic rulers.
Aside from this it seems more clear to me now that like in South India the Brahmins of the east are also relatively new and intrusive. All show an elevation of "European," though the trace of "East Asian" suggests admixture. That probably indicates their arrival after the absorption of the Mundari populations, and perhaps Tibeto-Burmans, into the substrate of eastern India.
I find nothing important to say here aside from the fact that we need a lot more samples for UP! The UP Kayastha indicates that there's a fair amount of variation here which is not being sampled.
We are obviously rich in samples from South India. One interesting aspect is the bias toward "SW Asian" as opposed to "European" among non-Brahmins, especially what I think are termed "Forward Castes" (e.g., Reddy). The proportions are low, but consistent. This is the inverse of what we see among non-Brahmins in East India. I am liable to dismiss the the East Asian admixture among many South Indians, especially non-Brahmins, as noise, but it may be signatures of absorbed Mundari substrate. Who knows? The Kerala Christian samples have the most "SW Asian." We need better references from other non-Brahmin non-tribal/Dalit castes in Kerala (a Nair is coming up), but I wonder if this validates the idea of some Semitic admixture of yore among Nasranis (or, perhaps just as likely long term trade and marriage connections over the centuries).
Now let's just look at South Indian Brahmins.
Very similar, huh?
Finally, the last cluster in western India:
Not much to go on, though I've been told that several of the Gujaratis are Patels.
Overall I think we can reject a strong recent post-colonial social construction of caste as a plausible model going by genetics. What replaces it? There probably won't be a neat model. But hopefully as HAP expands it can fill in some of the gaps. The 1000 Genomes Project will be releasing Assamese Ahom, Bengali Kayasthas, Marathas from Maharashtra, and Punjabis from Lahore, this year.
Related Reading:
This rejects a maximal claim, especially for Brahmins, but for that group that was never a good assumption to begin with.
Trickier are claims in between. Susan Bayly for instance has argued (Caste, Society, and Politics in India) that large sections of the peasantry, particularly in recently cultivated areas, acquired a jati identity only relatively recently. This is trickier to tell. Brahmin/non-Brahmin identity is very different in the South; but that's in large part a legacy of the fact that Southern Brahmins owe some northern ancestry. The situation in Punjab for instance is more mixed; maybe caste identity has been more fluid there?
It does seem that caste/non-caste populations have very different population histories, and various groups have maintained endogamy for a long time. One way to clear this up would be to digitalize the records at Haridwar and track surnames.
I (HRP0003) belong to one of the supposed in between peasant castes (Bhumihar Babhan) that acquired a "somewhat ambiguous" Brahman identity, as per Bayly, in the eighteenth century. http://books.google.com/books?id=HbAjKR_iHogC&pg=PA200
I think you make a good observation regarding the elevated SW Asian among forward caste, socially dominant South Indians like the Reddys. In the future we might have some Kamma participants, so we'll see if this trend continues to persist among them. Reddys and Naidus (unfortunately, we have no Naidu samples as of now) have been described as chieftains who prevailed among the Vijaynagar Kshatriyas who's modern descendants are likely represented by the Nayak and Raju castes of Andhra Pradesh and Karanataka. Likewise, the Kallars and Vellalars of Tamil Nadu used to serve as chieftains under the Cholas. Strangely enough though, HRP31, who's a Sri Lankan Vellalar is only 2% SW Asian and 1% European, much too little to be considered anything significant, and was only 2% more Baloch/Caucasus than the average Sakilli/Chakilliyan Tamil in the standard K=12 runs. Of course, n=1 is hardly a sample to make any concrete conclusions.
Regarding the SIBs, while they seem to be rather similar in terms of general admixture proportions, their inferred ASI scores seem to vary a bit. Tamil Brahmins seem to be around 38-40% ASI whereas the non-Tamil, Pancha Dravida Brahmins range anywhere from the 35% to 40%.
BTW, from what I've read the Halai Bhatia (HRP108 is one) are also Sindhi Rajputs, like the Thathai Bhatias. Hence I think Sindhis; n=3, not 2.
Razib, thank you very much for the post. We, Assyrians, as you know, are also, much to our surprise, a 19th century invention of the West. I honestly believe this might have contributed to the apparent lack of interest in our genome, by the academic community. Jewish populations, Druze, Samaritans, Arabs, Iranians, Kurds, Turks, Maronites, and others, have all been subjects, some multiple times, of academic studies. Without Harappa, Eurogenes, Dodedad, and the rest, we would still be an unknown, or, our identity significantly misunderstood (ie believing we are simply Christianized Kurds or Arabs).
The Kerala Christian "SW Asian" values are interesting. I recently received my father's Dr. McDonald analysis.
The following are possible population sets and their fractions, most likely at the top:
Bedouin = 0.098 Armenian= 0.860 Finland= 0.000 S_India= 0.042
Bedouin = 0.101 Armenian= 0.845 Sardinia= 0.009 S_India= 0.045
Bedouin = 0.101 Armenian= 0.851 Finland= 0.000 N_India= 0.047
Bedouin = 0.102 Armenian= 0.848 Basque= 0.001 N_India= 0.048
Bedouin = 0.108 Armenian= 0.826 Sardinia= 0.014 N_India= 0.052
Bedouin = 0.113 Armenian= 0.790 Sardinia= 0.025 Sindhi= 0.071
Bedouin = 0.099 Armenian= 0.845 Lithuani= 0.000 Sindhi= 0.055
Bedouin = 0.107 Armenian= 0.824 Basque= 0.009 Sindhi= 0.060
Druze= 0.351 Armenian= 0.592 Chuvash= 0.000 Sindhi= 0.057
Druze= 0.293 Armenian= 0.673 Tuscan= 0.000 S_India= 0.034
To add more intrigue, I recently came across the name Beth Hindawaya in a list of surnames of residents of a particular Assyrian (now predominantly Chaldean Catholic) village in northern Iraq. Beth Hindawaya means "House of the Indians" in our Aramaic dialect. I have no known link to the town, but it certainly does suggest Nasranis were living among us in northern Mesopotamia.
paul, i'm sure you know that the syrian christian community was originally in communion with the church of the east, right? the jacobite connection only was formed after the rupture due to forced catholicization during the portuguese period.
also, just to note, ancient sumerian documents do list tax receipts from villages where the "merchants from meluhha" settled. so a connection between south asia and mesopotamia may be ancient....
Thanks, Razib. That is indeed interesting. On the topic of the Sumerians, the one Mandaean with Y-DNA results reported at FTDNA has a distinct hg H haplotype. Although I believe Mandaeans are a principally central to northern Mesopotamian people, the fact they lived in southern Iraq for possibly the ~1800 prior to the most recent Iraq war, creates some intrigue. But, then again, where did the Sumerians originate? And, were they a homogeneous group, or a heterogeneous mix of different types at the end? Did any of their remnants remain at the end of the Babylonian civilization?
There is also some haplogroup H among Iranians, of course.
And, I expect the Y-DNA results of two new Mandaeans within the next few weeks.
Paul, here is a link to Al-Hindya http://en.wikipedia.org/wiki/Hindiya my tribe traces an oral history to this place. a few of them moved as recent as 1932 (to afghanistan/nwfp/kashmir/punjab), after iraq got independence from Britain.
these people also went with the honorific title of 'hussaini-brahmins'
if you do come across more research on this i would be interested.
Arjun,
Is your gotra parasara?
Thanks.
Paul, as an Assyrian, what are your thoughts about the various Christian and Jewish groups whose mother tongue is Arabic, that live as minorities in various Arab countries? Do you regard them as Arabs? If not, what are their ethnicities according to you?
that live as minorities in various Arab countries
Actually many of them live as diaspora populations in the West today.
There are also significant numbers of them, especially Jewish ones, that live in Israel.
Hi Onur. This question is a virtual minefield among many of the Aramaic-speaking communities of today. I would absolutely never tell anyone how he or she should or should not identify. How one wishes to identify, as you know, is a complicated matter. If you know any of my various fora monikers, feel free to pm me, and I will be happy to continue the conversation as it relates to my own people.
I will be happy to continue the conversation as it relates to my own people.
Thanks, Paul. But I think today there is no ethnic identity problem in Assyrians, as they still speak Neo-Aramaic instead of Arabic as mother language. Among non-Muslims and non-Druze of the Greater Middle East, I think the only ethnic identity problem is with the Christians whose mother language is Arabic - especially those of the Levant. Jews whose mother language is Arabic have largely overcome that problem by migrating to Israel and switching to Modern Hebrew as mother language. Copts largely see themselves as a direct continuation of the Ancient Egyptians, no matter what their current mother tongue is. But Levantine Christians have ethnic identity problems (probably partly because that the Levant has been an ethnically heterogeneous region throughout most of its history; moreover, there were Christian Arabs in the Levant, especially in its southern part, before the Muslim Arab conquests).
Dear Rajib i am from ghatal west bengal and ofcourse a brahmin. But i must tell you that from rg vedic times castes were not made by colour, race or noses shape! But by your abilities! even by having ability low born guys like vyaasa, vashistha became the supreme sages of all time and they also had their gotra. Unfortunately in later times the flexibility of the caste system got corrupted.
Razib, in your North India ADMIXTURE bar graph compilation, you have miscounted the Jatt participants. At the time, there were only three Jatts who had been run for K=11. The fourth Jatt you have included in the image is HRP006's results using his FTDNA Famiy Finder data.