Tibeto-Burmans in Bengal, and Indians in ancient Malaya

Thanks to the Singapore Genome Variation Project, and some data from Lynn Jorde‘s lab, I added some Tibetans and Malays for a pooled data set of East, Southeast, and some South Asians. The marker density was 70,000. I was curious to explore the various contributions of ancestry from eastern Eurasians into northeast South Asia.

The Tibetans, in particular, seem to be a common “source” population in a lot of places. There are fewer than 10 million Tibetan people, proper, today. But the impact of Tibetan or quasi-Tibetan people historically has been much greater than their current numbers might suggest. Additionally, Tibetans occupy a very wide geographical range, far outside of the Tibetan Autonomous Region of modern China. The majorit of ethnic Tibetans live outside of its political boundaries. The terms “Sino-Tibetan” and “Tibeto-Burman” are both ethno-linguistic terms which point to the affinities of Tibetans in a broader East and Inner Asian context. Not only was the Tibetan Empire of the 7th to 9th centuries a major geopolitical power, but the Tangut state which dominated much of modern Gansu for centuries had Tibetan affinities.

Meanwhile, in the northeastern quadrant of South Asia, Indo-Aryan languages are dominant today. But, Tibeto-Burman, Tai, and Austro-Asiatic languages are all important as well (or at least present). As noted in Strange Parallels, the Tai are most recent arrivals in Southeast Asia proper. This is known from history.

For Southeast Asia various archaeological, philological, and now genetic, data suggest that Austro-Asiatic languages arrived with the first farmers, who emigrated from what is today southern China, in the range of 4,000 years ago. The arrival of Tibeto-Burman languages and peoples to Southeast Asia surely precedes that of the Tai, which dates to 1,000 years ago, but likely postdates the arrival of Austro-Asiatic groups.*

The situation in northeastern South Asia is somewhat confused in terms of period of arrival of the various groups. A few years ago a paper on cholera genetics in Bangladesh reported analysis which indicates that the ancestors of eastern Bengalis received an admixture pulse of East Asian ancestry about 1,500 years ago. And, that a pulse model would suffice. An immediate explanation that came to mind is that these Bengalis mixed with Munda people, who have substantial East Asian ancestry, and speak an Austro-Asiatic language.

In The Genomic Formation of South and Central Asia one model for the emergence of Munda people that fits the data is:

1) An admixture of East Asian people (presumably, Austro-Asiatic farmers), with “Ancestral Ancestral South Indians” (AASI). AASI being indigenous South Asians who lack any West Eurasian ancestry.

2) A mix of this component with “Ancestral South Indians” (ASI), with consists of AASI and a minority ancestry of West Eurasian farmer from Iran.

Presumably there other models which fit the data as well, but even with naive admixture analysis it was long evident to anyone who looked at the Munda were atypical. The Turan/East European ancestry that one can find with classical model-based admixture at various levels in various South Asian populations is always absent in the Munda. Not only that, but they had very high fractions of modal South Asian ancestry combined with the East Asian component.

So can the East Asian ancestry in Bengalis be explained by the Munda? I’ve posted on this topic before, and every time I come to the same conclusion, probably not. Now that I have Tibetan and Malay samples to define a northwest-southeast transect I can say that again, more definitively.

At K = 10 in the admixture plot above you notice that the cluster modal in Malays and Cambodians accounts for almost all the East Asian ancestry in the Austro-Asiatic Munda sample. In Bengalis that component is found, but so is the proportion modal in Tibetans, and also in Han Chinese. The same pattern is found in the Burmese, but with much higher fractions. In fact, let’s compare average fractions between Bengalis and Burmese.

Han Tibetan Austro-Asiatic
Bengali 3% 4% 4%
Burmese 16% 34% 28%

The Han-model component is kind of general. We can’t reject the possibility I think from these proportions that the East Asian ancestry in Bengalis is exactly the same as that in Burmese…though based on Y chromosomal data I do think there is some Munda ancestry in Bengalis. Additionally, Munda people are found in some numbers even today in Bengal, into Bangladesh (the Santhals).

Looking at results from a three-population test the Tibetan(like) contribution to Bengalis seems likely:

outgroup pop1 pop2 f3 f3-error z
AustroAsiatic Dai Telegu -0.00187497 0.00012171 -15.4052
AustroAsiatic Telegu Lahu -0.00182418 0.000124765 -14.6209
AustroAsiatic Malay Telegu -0.00135077 0.0001035 -13.0508
AustroAsiatic Han Telegu -0.00138827 0.000112488 -12.3415
AustroAsiatic Telegu Kinh -0.00158805 0.000130918 -12.1301
AustroAsiatic Miaozu Telegu -0.00142974 0.00011907 -12.0076
AustroAsiatic Telegu She -0.0015296 0.000127609 -11.9866
AustroAsiatic Cambodians Telegu -0.00135761 0.000119312 -11.3786
AustroAsiatic Telegu Tujia -0.00137567 0.000125184 -10.9892
AustroAsiatic Telegu Naxi -0.00106498 0.000123643 -8.61336
AustroAsiatic Telegu Japanese -0.000991272 0.000116507 -8.50824
AustroAsiatic Yizu Telegu -0.00111008 0.000133985 -8.28514
AustroAsiatic Telegu Han_N -0.000844919 0.000122055 -6.92243
AustroAsiatic Telegu Tibetan -0.000414633 0.000109922 -3.77207
AustroAsiatic Telegu Hezhen -0.000428829 0.000116739 -3.67339
AustroAsiatic Xibo Telegu -0.000504054 0.000138498 -3.63943
AustroAsiatic Telegu Burmese -0.000335967 0.000108207 -3.10485
Bengali AustroAsiatic Iranian -0.00331738 7.5938E-05 -43.6853
Bengali Miaozu Telegu -0.00250784 6.12097E-05 -40.9712
Bengali Han Telegu -0.00250669 6.11899E-05 -40.9658
Bengali Telegu Tibetan -0.0022997 5.672E-05 -40.5448
Bengali Telegu Japanese -0.00240064 6.02193E-05 -39.865
Bengali Dai Telegu -0.00253233 6.53283E-05 -38.7632
Bengali Malay Telegu -0.00212941 5.51377E-05 -38.6199
Bengali Xibo Telegu -0.0023685 6.24874E-05 -37.9036
Bengali Telegu Han_N -0.00241445 6.40346E-05 -37.7054
Bengali Telegu Burmese -0.00205009 5.43997E-05 -37.6857
Bengali Telegu Naxi -0.00249315 6.66967E-05 -37.3804

OK, so what do we do with this, and how does it make sense? If you read a book like Land of Two Rivers, you won’t have any sense that an admixture between a Tibeto-Burman people, and Indo-Aryan speakers, occurred in eastern South Asia 1,500 years ago. To a great extent this is “prehistoric,” hidden from us, even if by that period mentions of the fringes of modern Bengal exist in Classical Indian sources. It is clear that many of the people who lived in Bengal were not part of Aryan society.  The later Vedic sources assert this explicitly, mentioning non-Aryan tribes beyond the march.

I currently believe that southern and eastern South Asia were touched by the expansion of Indo-Aryan/Dravidian speaking people after 4,000 years ago. This would make sense in light of the Vedic memory. I also suspect that Austro-Asiatic Munda people arrived after 4,000 years ago into a landscape where the population was AASI, without any West Eurasian influence. By 500 BC it seems that Indo-Aryan culture at least arrived on the edge of Bengal. At this date I suspect most of the tribes living in Bengal were probably already Munda. If the argument in The Rise of Islam and the Bengal Frontier is correct that much of eastern Bengal was not intensively cultivated until after 1000 AD. The period between 500 AD and 1000 AD was also the only one in ancient or medieval India where Bengal was home to the paramount hegemonic power in South Asia, a state ruled by the Pala dynasty.

Meanwhile, Tibeto-Burman people seem to have arrived to the east around 200 BC in the Irrawaddy basin. Rice cultivation in this region dates to 1500 BC. This is 500 years after rice cultivation arrived in northern Vietnam. Presumably then around 200 BC and later there was a transition from Austro-Asiatic languages to Tibeto-Burman langauges (the Mon may be intrusive from Thailand). Somehow I suspect that between 0 and 500 AD a group of Tibeto-Burmans moved up to the coast and arrived in eastern Bengal. Mixing with the native Munda they were probably absorbed by the expansion of Indo-Aryans eastward triggered by the political dominance of the Pala dynasty.

But was the gene flow in one direction? This seems unlikely. All the Burmese samples have South Asian admixture. This can be explained by proximity. But there are signatures of this in Cambodia, and the Malay samples I selected were part of a tight cluster. It seems that the Malay samples also have substantial South Asian admixture. The Indian Ocean economy and Diasporas between 0 AD and 1000 AD, after which Muslims and later Europeans became dominant, is a lacunae in our understanding. The presence of Malagasy and clear Austronesian influence in East Africa indicate a east to west migration. But Indian genetic signatures are found through Southeast Asia as well. Some of this can be chalked up to proximity (Burma) and colonial era contact (Malaysia), but Cambodia is too far for either to be plausible. Curiously, this influence is mostly lacking in Vietnam, or the interior of Southeast Asia. This is strongly suggestive of maritime trade contact. The regions where Indic culture were strong are the regions where there is a genetic signature of South Asians.

At this point I think I’ve established enough about South Asia and Bengal to move on from that. In the future I’m more curious about exploring contacts between South Asia and Southeast Asia, and how it left a cultural and biological impact.

* The 4,000 year date I arrival from the genetic sample and culture which emerges in northern Vietnam’s Red River Valley, and marks the transition between hunter-gatherers to agriculture.

Burmese are a bit Bengali

About ten years ago I read the book The River of Lost Footsteps: Histories of Burma. Though I have read books where Burma figures prominently (e.g., Strange Parallels), this is the only history of Burma I have read. The author is Burmese, and provide something much more than a travelogue, as might have been the case if he was of Western background. By chance over the past month or so I’ve been in contact with the author, who made a few inquiries as to the genetics of his own family (he came with genotypes in hand). But this brought us to the issue of the genetics of the Burmese people, and their position in the historical-genetic landscape.

The author of The River of Lost Footsteps reminded me of something that’s curious about Southeast Asia: its Indic influences tend to be from the south of the subcontinent. In particular, the native scripts derive from a South Indian parent. Could genetics confirm this connection as well? Also, could genetics give some insights as to the timing of admixture/gene-flow?

In theory, yes.

I had a lot of Southeast Asian datasets to play with, and did a lot of pruning to remove outliers (e.g., people with obvious recent Chinese ancestry). First, comparing them to Bangladeshis it seems that even without local ancestry tract analysis that Burmese and Malays have more varied, and so likely recent, exogenous ancestry than Bangladeshis. At least this is evidence on the PCA plot, where these two groups exhibit strong admixture clines toward South Asians.

But what about the question of Southeast Asian affinities? This needs deeper analysis. Three-population tests, which measure admixture with outgroups when compared to a dyad of populations which are modeled as a clade, can be informative.

Outgroup Pop1 Pop2 f3 z
Bangladeshi Telugu Cambodians -0.00183999 -46.3322
Bangladeshi Telugu Han -0.00220121 -46.046
Burma Telugu Han -0.00406071 -51.0018
Burma Han Bangladeshi -0.00348186 -49.1398
Burma Han Punjabi_ANI_2 -0.00418193 -47.2351
Cambodians Telugu Viet -0.00126923 -16.91
Cambodians Punjabi_ANI_2 Viet -0.00129881 -15.6039
Cambodians Bangladeshi Viet -0.000970022 -14.5642
Malay Igorot Telugu -0.00249795 -18.758
Malay Igorot Bangladeshi -0.00223454 -18.5212
Malay Igorot Punjabi_ANI_2 -0.00250732 -18.3027
Malay Igorot Cambodians -0.00107817 -16.6214
Viet Han Cambodians -0.000569337 -13.1139

Bangladeshis show strong signatures with both Cambodians and Han. This is in accordance with earlier analysis which suggests Austro-Asiatic and Tibeto-Burman contributions to the “East Asian” element of Bengali ancestry. The Burmese always have Han ancestry, with a South Asian donor as well. This aligns with other PCA analysis which shows the Burmese samples skewed toward Han Chinese. Burma is a compound of different ethnic groups. Some are Austro-Asiatic. The Bamar, the core “Burman” group, have some affinities to Tibetans. And the Shan are a Thai people who are relatively late arrivals.

Cambodians have a weaker admixture signature and are paired with a South Asian group and their geographic neighbors the Vietnamese. The Malays are similar to Cambodians but have the Igorot  people from the Philippines as one of their donors. And finally, not surprisingly the Vietnamese show some mixture between Han-like and Cambodian-like ancestors.

Further PCA analysis shows that while Cambodians and Malays tend to skew somewhat neutrally to South Asians (the recent Indian migration to Malaysia is mostly Tamil), the Burmese are shifted  toward Bangladeshis:

Click to enlarge

Finally, I ran some admixture analyses.

First, I partitioned the samples with an unsupervised set of runs (K = 4 and K = 5). In this way I obtained reified reference groups as follows:

“Austronesians” (Igorot tribesmen from the Philippines)
“Austro-Asiatic” (a subset of Cambodians with the least exogeneous admixture)
“North Indians” (Punjabis)
“South Indians” (A subset of middle-caste Telugus highest on the modal element in South Indians)
“Han” (a proxy for “northern” East Asian)

The results are mostly as you’d expect. In line with three-population tests, the Vietnamese are Han and Austro-Asiatic. More of the former than latter. There is a minor Austronesian component. Notice there is no South Asian ancestry in this group.

In contrast, Cambodians have low levels of both North and South Indian. These out sample Cambodians are still highly modal for Austro-Asiatic though.

Malays are more Austro-Asiatic than Austronesian, which might surprise. But the Igorot samples are highly drifted and distinct. I think these runs are underestimating Austronesian in the Malays. Notice that some of the Malays have South Asian ancestry, but a substantial number do not. This large range in admixture is what you see in PCA as well. I think this strongly points to the fact that Malays have been receiving gene-flow from India recently, as it is not a well mixed into the population.

The Bangladeshi outgroup is mostly a mix of North and South Indian, with a slight bias toward the latter. No surprise. As I suggested earlier you can see that the Bangladeshi samples are hard to model as just a mix of Burmese with South Asians. The Austro-Asiatic component is higher in them than the Burmese. This could be because Burma had recent waves of northern migration (true), and, eastern India prior to the Indo-Aryan expansion was mostly inhabited by Austro-Asiatic Munda (probably true). That being said, the earlier analysis suggested that the Munda cannot be the sole source of East Asian ancestry in Bengalis.

Finally, every single Burmese sample has South Asian ancestry. Much higher than Cambodians. And, there is variance.  I think that leads us to the likely conclusion that Burma has been subject to continuous gene-flow as well as recent pulses of admixture from South Asia. The variation in South Asian ancestry in the Burmese is greater than East Asian ancestry in Bengalis. I believe this is due to more recent admixture in Burmese due to British colonial Indian settlement in that country.

The cultural and historical context of this discussion is the nature of South Asian, Indic, influence, on Southeast Asia. One can not deny that there has been some gene-flow between Southeast Asia and South Asia. In prehistoric times it seems that Austro-Asiatic languages moved from mainland Southeast Asia to India. More recently there is historically attested, and genetically confirmed, instances of colonial Indian migration. But, the evidence from Cambodia suggests that this is likely also ancient, as unlike Malaysia or Burma, Cambodia did not have any major flow of Indian migrants during the colonial period. One could posit that perhaps the Cambodian Indian affinity is a function of “Ancestral South Indian.” But the Cambodians are not skewed toward ASI-enriched groups in particular. And, I know for a fact that appreciable frequencies of R1a1a exist within the male Khmer population (this lineage is common in South Asia, especially the north and upper castes).

As far as Burma goes, I think an older period of South Indian cultural influence, and some gene-flow seems likely. But, with the expansion of Bengali settlement to the east over the past 2,000 years, more recent South Asian ancestry is probably enriched for that ethnolinguistic group.

I’m going to try and follow-up with some ancestry tract analysis….

South Asian gene flow into Burmese and Malays?


I happen to have a data set merged from the 1000 Genomes and Estonian Biocentre which has Malays, Burmans, and other assorted Southeast Asians, East Asians, and South Asians. In light of recent posts I thought I would throw out something in relation to this data set (you can download the data here). Above you can see the populations in the data. You see Bangladeshis consistently are shifted toward Southeast Asians in comparison to other South Asians. But both Burmans and Malays exhibit some shift toward South Asians.

I ran ADMIXTURE at K = 4. Click the image for the larger file which shows the populations, but I will tell you what’s going on.

The yellow to green represent a north-south axis in East Asia. The Han sample is mostly yellow, but there is a green component in varying degrees. This almost certainly represents heterogeneity in the Han sample of north to south Chinese. The green component is nearly ~100% in some individuals from indigenous tribes in Borneo, and balanced with the yellow among peninsular Malays. It is more at a higher frequency in Cambodia than in Vietnam or Burma, indicating the older roots of Khmers and their relative insulation from later migrations of Sino-Tibetan and Tai peoples.

The red South Asian component is found in many Southeast Asians, but curious in the Burmans and Malays there is a lot of variation within the population. That indicates admixture over time that has not homogenized throughout the population.

I ran Treemix with 5 migration edges and French rooted (1000 SNP blocks out of 225,000 SNPs) and they all looked like this. Commentary I will leave to readers….

Rohingya unmasking complexity in a world we want simple

There is currently a major humanitarian crisis in Burma as Rohingya Muslims flee conflict between the military and separatist militants. Obviously this is a developing story. Unfortunately, very few in the West and the media have a well developed understanding of the history of Burma. Therefore the easiest framework is something worthy of a DC superhero film: there is the good, and there is the bad.

Just because such black and white dichotomies tend to collapse complexity doesn’t mean they are wrong. In World War II the Nazis were the bad. But details are often illuminating and informative. The Soviet Union was on the side against the Nazis, but it wasn’t exactly a “good” actor. Similarly, Finland at points made common cause with Nazi Germany, but that was less about its affinity with Hitler’s regime and more about surviving a Soviet invasion. There are people who are good and bad. But there are also people in situations, which dictate actions which are bad, or enable actions which seem good. (and a mix)

If you want a broader view of mainland Southeast Asian history, which Burma plays a large part in, I’d recommend Strange Parallels: Volume 1, Integration on the Mainland: Southeast Asia in Global Context, c.800-1830. Unlike Africa (with the exception of Ethiopia and Egypt), Indonesia, and much of the Middle East (Iran and Turkey excepted), mainland Southeast Asia developed nation-states organically. Vietnam, Cambodia, Thailand and Burma, were not dreamed up by European colonialists, but evolved through their own historical logic (in this case, the migration out of southern China of Tai peoples and the response of the older Southeast Asian polities, being the central narrative thread).

The only book about Burma’s history I’ve read is The River of Lost Footsteps. It has a lot of personal detail, as the author is himself a member of the Burmese Diaspora, and seems to come from an elite family with many connections the people who have run the country since independence.

In The River of Lost Footsteps the author alludes to the fact that Burma in the early modern period was on the edge of Islamicate civilization. At its peak the Mughal Empire had within its penumbra the Burmese polity, and it was impossible for the latter not to be influenced by the former (the influence actually pre-dates the Mughals, though intensified with them). The Buddhist kings of Arakan styled themselves sultans, and employed Muslims of Indian (or West and Central Asian) origin in their armies.

The descendants of these soldiers are part of the story of Islam in Burma. Too often the media representations of Islam in Burma reduce them to the Rohingya. The reality is that there are several Muslim communities within Burma, with different relationships to the majority Theravada Buddhist ethnicities. The River of Lost Footsteps claims that Aung San Suu Kyi herself (or more precisely her father) is in part from a family whose ancestry includes some of these Muslim soldiers.

Aung San Suu Kyi of course is at the heart of current events right now. Many are confused as to why this person, who has put her life on the line to defend the rights of self-determination of the Burmese people in the past, will not speak up for the Rohingya now. To a great extent this reminds me of the Lewis’ trilemma in relation to Jesus, that he was either a liar, lord, or lunatic. For many of us the answer may not be any of the above. Aung San Suu Kyi is a complex person at the heart of complex events. It was easy to portray her as a selfless saint, who was always on the side of the good as we understand it, but current events show that she was never immune to the exigencies of reality and practicality. Just as she was not saint in the past, I doubt she is a monster in the present, even if she has become caught up in events of monstrosity. Remember, if Gandhi was alive today he would surely be excoriated for his lack of solidarity with other people of color at least, and his racism at most.

Stepping aside from Aung San Suu Kyi, I think it is no surprise that democratization of Burmese society and culture has been occurring while there has been a rise in aggressive Buddhist chauvinism. Americans often do not want to admit that democratization and liberal tolerance do not go hand and hand. In places like China, and yes, Burma, authoritarian governments likely keep a lid on ethnic tensions because they are destabilizing for the public order. It was with universal white male suffrage in the United States that the racialized character of the American republic became much more explicit. Similarly, popular nationalism in Europe was associated with drives toward homogeneity and assimilation of subordinate groups.

Why are the Rohingya so hated in Burma? There are several possible reasons:

– They are racially distinct (all the photographs make it clear that they are not physically different from Bengali peasants) from most of the other ethnicities in Burma (including some groups of Muslims who descend from intermarriages with the Bamar majority).

– Their Muslim religion is very distinct from that of the dominant culture in Burma, Theravada Buddhism. Unlike China, where Buddhism is a strand within the national culture (and not a dominant one), in Burma Buddhism occupies the role that Christianity does in Northern Europe: the religion’s arrival was associated with the rise of complex societies, and political self-awareness. Though the Theravada Buddhism of Burma has local flavors (nat worship), it unites many of the disparate ethno-linguistic groups together, from the majority Bamar, to the Tai Shan, to the Austro-Asiatic Mon.

The Muslim religion of the Rohingya also enforces a stronger divergence from the majority religion than the Hindu background of other South Asians in Burma. Though most Indians left Burma in the years after independence, a substantial number have remained. The ethnographic literature I’ve seen indicates that many have re-identified as Theravada Buddhist, though no doubt maintaining many Hindu customs and practices within the community. This is not that difficult when you consider that Burmese Buddhism has many indigenous and Hindu influences already. Additionally, Hinduism and Buddhism are connected traditions, and arguably exhibit a level of commensurability that makes identity switching less stressful for both individuals and communities.

– They are perceived to relatively recent migrants to the Arakan coast from Bengal, and so not an indigenous ethnic community within Burma. Note that there are Muslim communities, even within Arakan, which are not Rohingya, which are recognized as indigenous. Not only are they perceived to be migrants, but their numbers threaten the dominance of the Rakhine people of the region.

In highlighting these elements I’ve suggesting that the Rohingya are arguably the most marginalized group in Burma. There are other Muslims ethnicities in Burma, but most are not demographic threats, derive from attested older migration events, and have intermarried with local populations so that the physical differences are not quite as salient. There are Christian minorities, such as the Chin, which have been targeted for persecution based on the religious differences, but the Chin are not perceived to be alien to Burma, simply unassimilated to dominant Theravada cultural complex. Additionally, there is no large racial difference between the Chin and the Theravada groups.

Much of the public debate revolves around the issue of Rohingya indigeneity or lack thereof. Though I have only modest confidence in my position, I believe that most of the Rohingya presence in Arakan dates to the period of British rule. Though the Rohingya language is not intelligible with standard Bengali, it is rather close to the dialect of southeast Bangladesh, Chittagong. My family is from Comilla, which borders the Indian state of Tripura. When I listen to Rohingya speak it’s only slightly less intelligible to me than the dialect of West Bengal (which is the basis for standard Bengali). In fact, the accent of Rohingya men is uncannily similar to what I remember from peasants in rural southeast Bangladesh when I visited in 1990!

If the Rohingya are not Bengali, they are something very close.

But the Rohingya will tell you something different. They do not self-identify as Bengalis, but as Burmese. Additionally, like some South Asian Muslims they deemphasize their South Asian origins, and create fictive extra-South Asian genealogies. It is important to note that the Rohingya do not write their language in the Bengali script. This means that their intelligentsia has no strong consciousness of being Bengali, because they are not part of the world of Bengali letters.

Earlier on I noted that mainland Southeast Asian had polities which easily transitioned to nation-states, because of the organic development of their identities. This is not true in South Asia. There is a bit of artificiality in the construction of South Asian polities (perhaps with the exceptions of Bhutan and Sri Lanka). Though South Asians no matter their identity are clearly defined and demarcated from other peoples, among themselves religion and community, rather than nationality scale ethnic identity, have been paramount.

In The Rise of Islam and the Bengal Frontier the author points out that a Bengali cultural identity evolved relatively slowly over the past 1,000 years. He makes the case that the Islamic character of eastern Bengal had to do with its underdeveloped state, and that land reclamation projects under the aegis of Islamic polities stamped the local peasantry who were settling the territory with the religion of the regnant order. And yet until recently the Muslim elite of Bengal was not culturally Bengali; they were Urdu speaking. The Bengali dialects of the peasantry were not prestigious, while the Bengali Renaissance was predominantly driven by upper case Hindus who helped shaped what standard Bengali became.

I will elide over the details of the emergence of a self-consciously Bengali and Muslim intelligentsia. It is something which I am only aware of vaguely, though I have seen fragments of it in my own extended family and lineage, as people from Urdu-speaking backgrounds have allowed their children to grow up speaking only Bengali, and fully assimilated to a Bengali identity without any qualification.

But the development of a Bengali and Muslim self-identity was occurring at the same time the ancestors of the Rohingya were pushing beyond the borders of traditional Bengal, into Arakan. Their lack of Bengali identity comes honestly because peasant identity has always been more localized and inchoate, and the Rohingya intelligentsia crystallized around other identifiers which could distance themselves from their relationship to Bengalis. In particular, the Rohingya seem more uniformly Islamic in their orientation. The female anchor for Rohingya news updates always seems to wear a headscarf, as opposed to those for Dhaka news reports.

In the short-term the killing of infants and raping of women has to stop. But these simple answers have behind them lurking deeper complexities. While agreeing upon the urgency of action now, we need to be very careful to not turn complex human beings into angels and demons. We have enough history in the recent past that that sort of model only leads to tragedy down the line, as those who we put utmost faith in fail us due to their ultimate humanity.