Swidden rice farming does not lead to high population density

Admixture on K = 5

I’ve been looking at the data from the recent Munda paper. Standard stuff, admixture, treemix, and f-statistics.The northern Munda samples were collected in Bangladesh. So I thought: I can test the hypothesis that the East Asian ancestry in Bangladesh is to a large part Santhal. After looking at it every which way, I think that in fact, the Munda may not have ever been very populous in much of northeast India. The Santhal is just not a good donor population to Bengalis, at least not when comparing mixes such as Dai + Tamil.

Additionally, the Santhal are really not that well modeled by mixing South Asians with any particular Southeast Asian group, though it works. I think that’s suggestive of the possibility that the Austro-Asiatic group which gave rise to the Munda don’t exist in their current form anywhere in Southeast Asia. Additionally, the Lao samples that are provided in the new paper I think may have Indian ancestry via admixture from Austro-Asiatic Mon or Khmer groups.

Basically, there is so much bidirectional gene flow that I think it’s really hard to get a grip on what’s going on. Additionally, the Burmese and northeast Indian populations (e.g., the Mizos) clearly have a strand of ancestry that derives from relatively recent migrants that came down from the region of eastern Tibet, and perhaps Sichuan or even further north. And this component shows up in Bengalis as well.

On top of this, there is the “Australo-Melanesian” substrate that is present all across Southeast Asia, and probably was present in modern southern China in the early Holocene, which has distant affinities with the “Ancient Ancestral South Indians” (AASI).

At this point, I keep my own counsel. But there may be an interesting story to tell related to how efficient and effective different forms of agriculture were, and how that interplayed with genes and language.

6 thoughts on “Swidden rice farming does not lead to high population density

  1. @Razib. Should we, Bengalis, consider ourselves as having some affinity to Han Chinese, as in, we are somewhat ‘racially’ connected to them (I’m 15-17% East Asian) even though we owe most of the East Asian ancestry to Austro Asiatic Farmers who although migrated from Southern China to SE Asia, they are quite distant from Han Chinese (lets be honest, an indigenous Cambodian doesn’t really resemble Chinese)?

  2. You realize, I hope, that many of your readers are utterly clueless about the ethnic geography of south/south-eastern Asia.

  3. On the topic of efficiency of forms of agriculture and mobility of agriculture, the Oakaie site in Burma at about 3700-2400 ybp which on PCA “projects close to present-day Myanmar and other Sino-Tibetan speakers” (Lipson 2018) shows that Sino-Tibetan ancestry must have been in SE Asia quite early and there are already people who are akin to Burmese in their level of “northern” ancestry….

    But I wonder if the form of agriculture practiced by Munda speaking groups (swiddening?) was much more suited to long range dispersal, if not high densities?

    Also seems really important on this topic to understand where the Naga peoples from NE India fit into this picture. The only sample of them I believe I’ve seen analyzed in a pan-East Asian context is the Harappa Project, where the Aonaga and Nysha samples came out with almost as much “NE Asian” (really Japanese) component as Northern Han Chinese, more “Siberian” component and less “SE Asian” component, and only 3-5% of S Indian component (vs Burmese at about 15% and Cambodians at 8%), in general seemingly being “north” of Northern Han on the East Asian cline. (See K=17 here – https://www.harappadna.org/2011/11/ref3-yunusbayev-caucasus-data-admixture/ or something). When did they arrive in NE India and how?

  4. Also seems really important on this topic to understand where the Naga peoples from NE India fit into this picture.

    there is a naga in the ‘east indian’ sample. and yes, it’s weirdly northern

  5. I realize that swidden farming has no real role in this post, but Chotanagpur plateau is not very forested (https://en.wikipedia.org/wiki/Chota_Nagpur_Plateau#/media/File:Chiraundi_-_Ranchi_8709.JPG).
    So, swidden or slash and burn is not a particular form of rice cultivation (An Ethnolinguistic Study of Munda Rice Cultication in Jharkand, India, Toshiki)at Chotanagpur. The more precise definition is upland rice cultivation.

    The idea of Munda as rice cultivating itself is unclear. Today they do not cultivate rice. The literature has gone considerable variation, as Doruan fuller explains here (http://archaeobotanist.blogspot.com/2010/07/dialog-on-rice-in-indian-cultural.html) “In either case Proto-Munda agriculture was not particularly rice focused, indeed reconstructible rice vocabulary is meagre, but focused on tubers (including taro), millets (and it is unlcear if these are the Chinese or Indian millets originially), and pulses, water buffalo and maybe pig. It seems clear that Proto-Munda is heavily influenced by Dravidian and pre-existing Indian agriculture through the adoptions of sheep/goat, zebu, and Indian pulses”.

    However, this does not take away from the original idea: upland farming is not capable of supporting large populations as wetland rice farming; and thus, Munda or Santals are not numerically large. The same idea bears repeating in Kerala, Bengal, and the valleys of Andhra: the wetland rice farmers swamped the natives.

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