Tuesday, November 9, 2010

Multidimensional scaling in Italy, the Balkans, Anatolia, and the Caucasus + Lezgin ADMIXTURE surprise

On the left you can see an MDS plot of several population groups from Italy, the Balkans, Anatolia, and the Caucasus. This combines data of Dodecad Project members with published samples. I have placed the labels manually over the main point blobs. There is also a single Bulgarian sample who falls between the 'm' and the 'a' in 'Romanians'.

I had previously studied the distinctiveness of Caucasus populations, and now I have added Turks, Cypriots and populations from further West. I am still not satisfied with my Balkan samples (I have 2 Slovenians, 2 Serbs and 1 Bulgarian), so I encourage Balkan participants to contact me for possible inclusion in the Project.

When I turned to ADMIXTURE, a little mystery emerged, for which I have currently no explanation:

Two main components emerged, a light blue "Italo-Balkan" one that seems deficient in West Asia, and red "Cypriot" one that is deficient in West Balkan Slavs and the Caucasus. The three Caucasus populations, each form their own distinctive cluster (green, yellow, blue), and a magenta low-frequency component emerges at K=6, which is why I stopped the analysis at this K. Results for K=5 were similar, minus this low-frequency component.

Here is the big puzzle: my Bulgarian, 2 Serbs, 2 Slovenians, all show unambiguous membership in the green "Lezgin" cluster. Out of all the Caucasus components, this is the only one that seems to have a Balkan connection. While one could argue that this might reflect Neolithic farmers, as it has been argued that they spoke a North Caucasian language, the same "Lezgin" component is insignificant in Greeks and Mixed-Greeks, Southern Italians/Sicilians and Italian (other).

Is this some signal of a population that once inhabited the northern arc of the Black sea, from the Balkans to the Caucasus? This might find some support in the possession by both Lezgins (and Balkan Slavs) of a "North European" component, but the Adygei, who similarly possess such a component show no special affinity with Balkan Slavs. Below is the Lezgin K=10 portrait:
If anyone has any (pre)-historical scenario that might account for this unexpected affinity, feel free to write to me or leave a comment.

12 comments:

  1. I wrote a comment that just disappeared. But it was about the Dakians, that were wiped out by Romans 106 C.E. It was a genocide. Among the Dakians (in todays Romania. There lived also Celts, Iranians and Bastarns (one germanic people from far east)).
    A few surviving Dakians fled over the Karpatians. Romans populated the country with slaves afterwards.

    Maybe this doesn't fit at all, was just an idea I got.

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  2. Could the Pink be the Iranians - or a subset of them. Both the Serbs (Srpski) and Croats (Horvats) were Iranians tribes originally?

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  3. I think Admixture got mad this time: a redundant component + strange North Balkan - Lezgin connection. I would suggest you to add Lithuanians to this analysis to isolate "Slavic" component in these groups.

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  4. What about the traditional steppe-land nemeses? Huns, Avars, Kipchaks, Scythians? Perhaps you ought to add Hungarians, if you have enough, to the mix.

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  5. the lezgins are closely connected to the the caucasian avars

    http://en.wikipedia.org/wiki/Caucasian_Avars

    as everyone knows, the avars had a confederacy in southeast-central europe. the various south slavic peoples were once the subjects of the avars.

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  6. p.s. i'm aware that the term "avars" may denote very different people. the ethnic nature of the original european avars is still under debate. but the connection here is too suggestive to ignore.

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  7. I think we're looking at the effect of the Bulgur (Avar?) incursions into the Balkans:

    http://en.wikipedia.org/wiki/Old_Great_Bulgaria.

    There's a nice map of the ancient position of Old Great Bulgaria hugging the top of the Black Sea and running down toward Azerbaijan.

    The Bulgars are "recent". What's ancient is the very strong signal of the Italo-Balkan component in the Balkans.

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  8. Razib, what relationship do NE Caucasian-speaking Avars have with Turkic-speaking Avars of the Middle Ages?

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  9. Bolgars, Avars, slaves brought in by the ever ubiquitous Romans..

    Maybe the solution does not have anything to do with those extraneous peoples mentioned but may just be a sign of that low but detectable signature of the "South Asians" in Europeans. I don't mean Romani but peoples who had South Asian like genetic signatures who tagged along with other human movements into Europe, like the Neolithic farmers or the I.E speaking peoples from the Eurasian steppes.

    The Caucasian Avars and the Avars who spoke a Turkic language and invaded Europe are two different ethnic groups who just share a name. There is also Iberian Caucasus, Albanian Caucasus. Just similarities in names with no genetic links to the other.

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  10. This comment is about the MDS plot.

    I see that the Jewish folk are not included in this plot. Usually the Jewish folk slot in after the South Italians and the Cypriot Greeks. Were the Jewish folk left out for clarity in the plot of Europeans, Anatolians and Caucasians, and the fact that they are more recent ethnic groups composed of SE European, Anatolian and Middle Eastern elements? Their position indicates more their admixture rather than their origin in that part of the Mediterranean Basin.

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  11. 1. Please, don't mix up Early-Medieval Eurasian Avars (steppe nomads) with Caucasian Avars (highlanders). Hunns, Avars, Mongols were a mix of very different people, named after their ruling group, and can't be trteated as genetically homogeneous.

    2. Lezgins are more isolated neighbors of Avars.

    3. One, who speculates on nomadic connection between Lezgins and North Balcanians, should explain why Adygeis don't demonstrate it, while they were neighbors of Early Bulgars and other Pontic nomads for centuries.

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  12. My guess is that both south Slavs and Lezgins origin from Sarmatians

    tribal name Lezgin seems to be related to the name of Sarmatian tribe Lazyges/Iazyges

    http://en.wikipedia.org/wiki/Iazyges

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