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:
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….
As usual excellent analysis. Not surprised to see Burmese being shifted toward Bangladeshis, but the surprising part is Burmese south Asian percentage is higher than the Bangladeshis east Asian percentage.
As for Bangladeshis being “Mid-caste South Indian + North Indian Punjabi” I guess, the former came from Indus Valley and brought Iranian Farmer and AASI genes to Bengal and the latter brought some Steppe genes as well, which means Burmese also have some Iranian Farmer,AASI and Steppe ancestry. Burmese must be the most Western Eurasian shifted among SE Asian groups and their geographical location also confirm it.
I don’t understand why North Indian, South Indian, Austroasiatic and Han bars are not uniform in all Bangladeshis, when the steppe and East Asian ancestry is of similar amount in all Bangladeshis. The Han ancestry might increase in eastern Bangladesh and decrease in western Bangladesh, where Austroasiatic might increase.
Are Igorot samples on both plots? Can’t see them on PC1 vs PC2.
Shape of PC2 seems a little unusual – PC1: East Asian vs South Asian, PC2: Cambodian vs Han+South Asian, most Malay samples closer to Han than to Cambodian?
Using the data from the Eurogenes Global25 has found a different shape (though with different samples of course): https://imgur.com/a/9rcfHVb
(Method something like this, with different populations: https://eurogenes.blogspot.com/2018/05/global25-workshop-2-intra-european.html)
What about Chola kingdom? Wouldn’t that explain R1a1a in Khmer? Or you meant not just British colonial when you wrote colonial?
Still can’t tell difference between pink of Telugu from pink of Viet or Burma.
“What about Chola kingdom? Wouldn’t that explain R1a1a in Khmer? ”
R1a1a is present even among non-Brahmin south Indians, so it would not be surprising if cholas brought that haplogroup to Khmer empire.
There is an interesting piece of unsupported, manufactured history. The Mon people were the original occupants of the Irrawaddy valley 1500 years BP before being displaced by Bamar in 1057 AD. A confusing history of the Mon people was they were known as Talaing which people have interpreted as a corruption of Telugu or Telangana. This is of course a bit off since the Mon people came from South, Chao Praya river and from the east, but their original language and current script is based on Pali with a number of words from present day Orya. When the Bamar overran the Irrawaddy valley, the Mon men were displaced eastwards into the dead-ended region between the mountains and Andaman sea, but the women were subjugated. Now, the Mon people were original recipients of indian culture some 1500-2000 BP from East coast of India through Y-dna of travelling Indians and hence the nomenclature of Talaing. Thus, the present day Bamar were stuck with Y-DNA contributions from Indian men 1500-2000 BP.
Of course, most of the extant mtDNA in India is quite ancient, and the Metsapalus/Kivsid say they were shaped by early human settlement in Eurasia. There is uncertainty whether the settlement occurred in a straightline Iran->India>south east axis or Iran->Bypass India->Southeast Asia->backflow to India axis.
Here, you should refer back to your http://blogs.discovermagazine.com/gnxp/2011/07/southeast-asian-migrations/ and the comments.
“I believe this is due to more recent admixture in Burmese due to British colonial Indian settlement in that country”
Unfortunately there was not considerable mixing; the Indian population in Burma census was 6-7% in 1931 (about 630 K) but nearly 80% of the population was repatriated twice, first in 1949-50 and then in 1962 about 2 million individuals; the left over indian population was about 800 K -1 million in 1991, with very limited mixing. Casteism, religious differences limited this admixture, quite similar to Indians in malaysia.
@Vijay, before you criticize Razib, what you have provided is itself an extremely fast and loose description of the history of Burma. You have left out the Tibeto-Burman speaking Pyu city-state which dominated much of the country well before migrations of Bamar into Burma – https://en.wikipedia.org/wiki/Pyu_city-states.
Samples from Oakaie sites in the NW (around 2700 BP) already seem to demonstrate a greater closeness to Tibeto-Burman speakers from SW China and to present day Burmese samples than to present day samples of Cambodians, Nicobarese or any Austroasiatic / Mon-Khmer people http://science.sciencemag.org/content/early/2018/05/16/science.aat3188.full
Austroasiatic groups may or may not have preceded Tibeto-Burman speaking groups in Burma (this is unclear; on the one hand, the extremely Austroasiatic character of the East Asian ancestry AA speaking groups in India, lacing Tibeto-Burman elements is some evidence for this, on the other it’s not perfect as migrations into India may have taken a specific route where people didn’t meet and even where they did ancient dna shows admixture along migration routes doesn’t always happen).
But politically the Mon Kingdoms do not precede the Pyu City States in Burma, and if anything long post-date them, seem to be a relatively late intrusion from the south and east, not long in history before the migrations of the Bamar. And on the basis of genetic evidence, any Austroasiatic speaking people had likely long since ceased to make up large shares of the population in Burma long before any migrations by the Bamar.
Read some history – https://en.wikipedia.org/wiki/History_of_Myanmar. Super simple stuff.
First off, thanks for free advice to read history on Wikipedia. I appreciate the advice, given I spent 7 years in Rangoon in elementary and high school.
I have never criticized Razib, but just pointing some ways whereby Indian intrusion into Myanmar could have worked. The Pyu and Mon kingdoms are two possible people that could have had indian intrusion, genetically.
Of the two, the Pyu people were the original, but the population size (12 settlements 30-50 ha; I have visited the one near Pyay. The population mention in Wikipedia is 200 K, but I doubt if all the settlements are from the same time, and doubts exist whether they exceed 100 K. Secondly, reliefs show the pictures of the people; whereas the gods have Indian features, those of the people are entirely Tibetan or Burman. That is the reason why I think the cultural influence on Pyu was large but genetic impact on the Pyu might have been smaller as regarding the influence on present day Burman.
The impact via Mon has similar issues, the Mon population was also from Thailand, but reliefs show that the Mon-Talaing had closer features to present day Burmese but a smaller religious and cultural influence.
The only place I differ from razib was the post-colonial; Indians and Burmese did not interact in a big way in colonial Burma. The differences were religious, cultural and lingual. Surprisingly, the Burmese were well mixed, but will not accept the Indian as equal. There was a feeling that those that relocated were not the original Indians. The lack of interactions with Indians will spill over in 1949 and 1962 as major expulsions.
There is another point I had not discussed: both, present day Burman and tibeto-Burman intrusion into Bengal may have originated from the same population, but that is another difficult issue.