Indian Cline II

One thing I forgot in the post yesterday about the Indian cline was to try to extrapolate from the PCA results to 100% ANI (Ancestral North Indian) and 100% ASI (Ancestral South Indian).

This is a simple linear extrapolation which should be okay since PCA is linear.Men's Club - Онлайн Журнал

The "N" denotes the extrapolated position of ANI and "S" denotes the ASI. The points to the left of "N" are all Utahn Whites while the Onge are on the bottom right of the graph.

As you can see, the ASI is about the same as Onge in terms of eigenvector 1 (which represents the Indian cline approximately), but ASI is far from Onge on the 2nd eigenvector. That is expected since the Onge have been separated from the mainland populations for a long time.

The more interesting thing is that the extrapolated position of ANI is a little to the right of all the Utahn Whites.

We'll need a similar analysis of the Indian cline with more populations to see which one the ANI is closest to.

PS. I should point out that I am using correlation between a limited number of population statistics to find a relationship between the 1st principal component and Reich et al's ASI estimate. This has a number of drawbacks. It would be much better to compute ASI directly.


  1. Excellent work. Would the introduction of West Asian groups distort the results, and if you do introduce it along with the CEU, do you think ANI will cluster closer with the former or the latter? Do you think it is possible to carry out such an exercise?

    • I plan to carry out such an exercise.

      As for being confident of the results, I won't trust them until I am doing ANI-ASI analysis independently of Reich et al. Till now, both I and Dienekes have used the Reich results to infer ANI/ASI.

  2. I think there's a way to find S independent of Reich et al. The West-Eurasian/ASI Indians form one cline from CEU while the East-Asian/ASI (Austro-Asiatics) forms another cline from CHB. The intersection point of the two clines is where S might be located as apposed to what Reich's et al. premises place it. See figure S5 pp 13 in the supplement.