Thanks to all the participants of the Project, the number of populations has increased, and so have sample sizes within pre-existing populations in the Project. There are now 17 populations with at least 5 individuals in the Project:
Assyrian, Scandinavian, Greek, Finnish, S_Italian_Sicilian, Ashkenazi, German, Indian, Portuguese, Armenian, Russian, Spanish, British, Irish, Turkish, N_Italian, BalkansBelow are the K=10 ADMIXTURE results with these populations:
Admixture proportions can be found in the spreadsheet.
The fact that the addition of 17 populations and 143 individuals to the core set of 36 populations and 692 individuals results in the same 10 ancestral components testifies to the stability of this solution. Hopefully, within 2011 I will develop an even better comparison set to work with.
Another test of the validity of the analysis is comparison of independent samples of the same populations:
Ashkenazi, Armenian, Spanish, Turkish, N_ItalianI have a sample of Dodecad Project members for each of the above, as well as a published population. A way to measure the concordance between the two is to calculate the correlation coefficient (rounded to the 3rd decimal point):
- Ashkenazi Jews: 0.999
- Armenians: 0.988
- Spanish: 0.998
- Turkish: 0.995
- N_Italian: 0.996
I have also made a RAR of "population portraits". It is important to do this to determine whether minor ancestral components represent population-wide phenomena or are limited to a few individuals.
For example, here are the Turks of the Dodecad project:
The sample is a bit more varied than the sample included in Behar et al:
This probably underscores the importance of broad coverage of large countries and ethnic groups, as I have discovered recently in my analysis of 9 different populations of Pakistan.
Another new population are the Irish, presenting a picture of remarkable homogeneity:
Here is the population portrait for the Balkans, which consists of non-Greek, non-Roma inhabitants of the Balkans:
This appears quite varied; hopefully more Balkan project participants will allow me to split this into additional sample populations.
Finally, here is a portrait of the Ashkenazi population, which appears quite similar to the Behar et al. one:
A very interesting thing about this population is the existence of small slices of "East Asian" and "Northeast Asian" components totalling about 1.5% in almost all individuals. In my opinion this testifies to some type of old minor absorption, as it is fairly evenly spread in the population.
If you haven't joined the project yet, feel free to submit your sample during this opportunity.