yes, ASI automatically results in an “east asian” signal. the key is to find a K where that signal disappears and the ASI is cleanly separated from other east eurasian groups. and “only 5%” is a lot because 1) they aren’t that east asian, 2) EDAR variant in east asia is not fixed everywhere.

1. Where do the dates of the ANI/ASI come from? Are they just hypothetical or is there some independent reason to assign the dates?
2. ASI is plausibly 10k BC because of the proximity to Andamanese tribes, right?
3. ANI is presumably farmer genes, but is this a guess or some independent evidence for this?
4. What is the evidence for ANI2? Why is this considered an overlay separate from ANI? Can this be correlated with Indo-Europeans (eg. show that it is not part of European farmer DNA, but a later migration in to Europe).

This is just for my own education. Thanks!

The Khasi could quite plausible be an tribe that is the result of the fusion of roughly equal numbers of people from a Munda language speaking tribe and a Tibeto-Burmese language speaking tribe. Tibeto-Burmese language populations generally appear to be least admixed of any of South Asia’s linguistic groups and also to be the most recent arrival to the mix. And, given the general tendency of Austro-Asiatic tribes to be in the general vicinity where we would expect a Tibeto-Burmese population migrating into South Asia to land, the geography wouldn’t make this kind of fusion particularly unlikely.

One would still have to account for the small Siberian and European components, but there are a variety of ways that these components could have introgressed into a pretty small founder population and then taken on an abnormally large percentage, assimilation of a literal handful of defecting Indo-Europeans (pre-admixture with South Asians) in a scouting or missionary group, into a couple of reproductively successful families of either of the pre-fusion populations, for example, could do the trick.

https://spreadsheets.google.com/ccc?key=0AuW3R0Ys-P4HdGI3V2Z0SEs5WmRPcVoybDJXNzRIWXc&hl=en#gid=3

this is the model i think would be most plausible of the munda represent the oldest stratum.

I like your reasoning but consider this. If the East Asian component was the earliest one, then it may have been associated with a different set of demographic parameters than the later, presumably Dravidian, component. The smaller effective population size of the East Asian component, which is more appropriate for Pleistocene foraging population structure, would make any gene flow from smaller and more sparsely distributed Munda to larger, more expansive Dravidians negligible and perishable. Or, alternatively, the original East Asian component in Dravidians simply had enough time to drift out. Even in the Munda the frequencies of the EDAR gene are low, which suggests that the West Asian non-EDAR component is close to edging out the East Asian one from the Munda. Notably, the Harappa dental sample – assuming that Harrapans were Dravidian-speakers – has moderate to elevated frequencies of shovel-shaped incisors (58%), which is one of the phenotypical features controlled by the EDAR gene common in East Asians. In West Eurasians, by contrast, shovel-shaped incisors get progressively rare being replaced by chiseled incisors instead. So, we may find evidence for the early East Asian component in Dravidians in some lucky places.
http://books.google.com/books?id=RTsXTy5aBgQC&pg=PA234&lpg=PA234&dq=shovel-shaped+incisors+south+asia&source=bl&ots=wTsuIrTELx&sig=FC3ht1J9BJEkMQ9l076jJI0_roA&hl=en&ei=yO20Tb6PBeLj0QHT1ZyzCQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCMQ6AEwAg#v=onepage&q=shovel-shaped%20incisors%20south%20asia&f=false

Razib, if I understand it correctly, the data could be read in the opposite way: The high concentration of the Onge component in Munda attests to the antiquity of Munda in India, possibly predating Dravidians and Indo-Europeans. Linguistically, Ongan-Jarawan has recently been shown to be related to Austronesian, which in turn, with Austroasiatic, is part of Narrow Austric. Narrow Austric is a decent superphylum with some solid cognates behind it. So, the high concentration of the Onge component in Munda simply means that both Munda and Onge are relics of an ancient, ultimately, East Asian population that expanded massively in SEAsia and Oceania but remained largely conserved in the Indian refugium. Munda then domesticated rice independently of the South China source.