Monday, November 8, 2010

Portraits of the populations

Averages give an overview of different populations' makeup, but they may mask important variation. Thus, I have decided to present the individual-variation of the various populations included in the Project. You can get a RAR file with all populations here.

Below, I will highlight a few ones. I apologize about the quality of the graphics, but these were generated by a script I wrote which doesn't seem to have the presentation controls of normal "Save As".

First, the Saudis:

You can see, for example, that the West African admixture in this population comes pretty much from 3 individuals, with one of them having a substantial chunk of it. Some individuals have South European or West Asian admixture, while many belong 100% to the Southwest Asian component.

Next, the Ashkenazi Jews:

You can see that some individuals have an excess of the North European component, while others have almost none.

Next, the Burusho:

These appear very homogeneous, with what variation we might expect from random hereditary processes or the limitations of admixture inference.

Next, the Romanians

I've commented on the presence of 2 probable Roma individuals in this population before, and this seems quite evident in this plot.

Finally, the Gujarati:

It is evident that the North European and East Asian element is limited to a few individuals, with most of them appearing to be a "South Asian" and "West Asian" blend. One might speculate that these represent individuals admixed with other subcontinental populations where these two components are more important.

10 comments:

  1. I downloaded the rar.
    There is lot of african admixture in the spaniard samples, much more than other S.europeans tested it seems.
    This goes along with many 23andme plot i have seen.
    They may have a bit more of north european bar than other southern samples but they have a lot more Africans than others.
    Tuscans and North italian samples have lot less if any sometimes.

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  2. It would be intesting to do the same with French and Spaniards as averages for such big countries are almost meaninglesss. Even if their North African averages are low, I am pretty sure that number can reach 5% or more in some samples.

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  3. Both French and Spaniards are in the RAR file.

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  4. Yes and as expected I see a French (64) and a Spanish (173) both with probably 5-10% North African ancestry.

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  5. Interestingly all the Saudis that do have an African admixture do also have a "south European"&"western Asian" admixture as well.
    The "pure" 100% "southwestern Asian" Saudis are interesting too.

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  6. Artu, it's not true that there is a lot of african admixture in Spaniards. First of all, it's east-african, which is not the same as saying "african". And second, it is very small. It is also surprising to see that French and other europeans having so much South Asian (dark purple)

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  7. Lol, let's shoot those French and Spaniards with the excessive North African! Have anyone ever thought that maybe the North African element in Europeans is more ancient and native to the circum Mediterranean region than the North European element is native to West Eurasia since it developed on the steppes of Eurasia, nearest European country is the back end of "European" Russia.

    The Maltese people should be 100% North African if you accept the Muslim Arab scuttlebutt yet I am 7% NW African after those centuries of occupation by Muslims. It is hardly worth any angst.

    Instead of fretting over the African content in French people particularly the autochthonous Caucasoid African content of Europeans, a people whose origins go back to the Paleolithic in Africa, I would be more concerned about the non Caucasoid content of other more northerly Europeans. I think you are showing your Freudian fears and strange preoccupations about what is African and what is Negroid.

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  8. Dienekes,

    Might those 2 "Roma" actually be Székely (aka Szeklers), and have an excess of "South Asian", which is really more Central Asian?

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  9. Truth, actually there is also northwest african and even some west african in the spanish samples.
    It may be few but it is more than other southern european samples.

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  10. @Ponto : "Have anyone ever thought that maybe the North African element in Europeans is more ancient and native to the circum Mediterranean "

    Yes of course, all 3 African components shared by many populations on both shores of the mediterranean are very ancient and have nothing to do with historical events. This just tends to prove that all these populations (Berbers, Iberians, Maltese, South Italians, Sicilians...) all share a common ancestry and all belong to the old mediterranean substratum ...

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