If you have not read my post “To the antipode of Asia”, this might be a good time to do so if you are unfamiliar with the history, prehistory, and ethnography of mainland Southeast Asia. In this post I will focus on mainland Southeast Asia, and how it relates implicitly to India and China genetically, and what inferences we can make about demography and history. Though I will touch upon the Malay peninsula in the preliminary results, I have removed the Indonesian and Philippine samples from the data set in totality. This means that in this post I will not touch upon spread of the Austronesians.
I present before you two tentative questions:
– What was the relationship of the spread of Indic culture to Indic genes in mainland Southeast Asia before 1000 A.D.?
– What was the relationship of the spread of Tai culture to Tai genes in mainland Southeast Asia after 1000 A.D.?
The two maps above show the distribution of Austro-Asiatic and Tai languages in mainland Southeast Asia. Observe that when you join the two together in a union they cover much of the eastern 2/3 of mainland Southeast Asia. The fragmented nature of Austro-Asiatic languages in the northern region, edging into the People’s Republic of China, implies to us immediately that it is likely that in the past there was a continuous zone of Austro-Asiatic speech in this region. From the histories and mythologies of the Tai people we know that this group migrated from the southern fringes of China around ~1000 A.D. This is obvious when we note that there are still Tai people in southern China, and the expansion of the Tai across what is today Thailand is to some extent historically attested. Between 1000 and 1500 there was a wholesale ethnic reorganization of the Chao Phray river basin. Was that a matter of demographic replacement, or cultural assimilation, or some of both?
Second, what was the impact of Indians upon mainland Southeast Asia? One of the easiest ways to ascertain Indian influence is script. Burmese, Thai and Cambodian scripts all derive from Grantha, an archaic Tamil script (non-Islamic scripts in island Southeast Asia, such as Javanese and Balinese, are also derive from South Indian precursors). The Indian religious influences also are more southern than northern, manifesting in the southern forms of Shaivite Hinduism and Sri Lankan Theravada Buddhism.
Markers show populations sampled by HUGO Pan-Asian SNP Consortium
The Pith: Southeast Asia was settled by a series of distinct peoples. The pattern of settlement can be discerned in part by examination of patterns of genetic variation. It seems likely that Austro-Asiatic populations were dominant across the western half of Indonesia before the arrival of Austronesians.
About a year and a half ago I reviewed a paper in Science which did a first pass through some of the findings suggested by the HUGO Pan-Asian SNP Consortium data set, which pooled a wide range of Asian populations. You can see the locations on the map above (alas, the labels are too small to read the codes). The important issue in relation to this data set is that it has a thick coverage of Southeast Asia, which is not well represented in the HGDP. Unfortunately there are only ~50,000 markers, which is not optimal for really fine-grained intra-regional analysis in my opinion. But better than nothing, and definitely sufficient for coarser scale analysis.
A few things have changed since I first reviewed this paper. First, I pulled down a copy of the Pan-Asian SNP data set. I’m going to play with it myself soon. Second, after reading Strange Parallels, volume 1 and 2, I know a lot more about Southeast Asian history. Finally, the possibility of archaic admixture amongst Near Oceanians makes the genetics of the regions which were once Sundaland and Sahul of particular interest.