Last year I was approached by someone from the Knanaya community of South India as to their genetics. The Knanaya believe themselves to be descendants of later Near Eastern migrants than the other Nasrani St. Thomas Christians (both communities seem to believe in some connection to Near Eastern Jews). The history of these communities is complex, but they are rooted in the Oriental Orthodox Christianity of Iraq and the Levant. You might be curious to note that the largest number of individuals associated with the Syrian Orthodox Church are South Indians.
For some context, I’d recommend The Lost History of Christianity by Philip Jenkins.
With some preliminary analysis, it did seem like the Knanaya community was enriched for Near Eastern ancestry, even compared to the other Nasrani samples I had. Recently I’ve been given a total of 11 samples of Knanaya, so I decided to do some further analysis (2 of the individuals seem somewhat related, so they are not independent data points).
If you look at the plot above, you can see that the y-axis is PC 3. This separates Northern European samples (Belorussians and Lithuanians) at one end and Yemeni Jews at the other. Groups such as Armenians are in the middle. You can see that some groups, such as the Mumbai Jews (Bene Israel), Cochin Jews, and, the Knanaya, do seem shifted toward the Yemeni Jews. Groups in the Levant and minorities like Assyrians are usually about 2/3 “northern” and 1/3 “southern” in ancestry.
To get a better sense of that, take a look at the Admixture barplot below.
This is a supervised run with several reference populations. The light blue are Yemeni Jews, and you can see quite clearly that the Knanaya show evidence of this ancestry, while most other Indian populations do not.
To get a sense of the ratio of northern Middle Eastern vs. southern Middle Eastern, here are the results for the Druze:
TreeMix is a little more ambivalent:
The flow to the Cochin and Mumbai Jewish groups is clearer (or from in the latter case). I think the history of the Kerala Christians, and the Knanaya in particular, is more complex.
I’ll probably run some more stats tomorrow to see what the best donor population is…