Wednesday, 11 May 2011

Old New World. Restricted pole run: Part II

The European results of my "restricted pole" supervised run of the Fertile Crescent area follow. This is the exact same run as this one.
I didn't include most individual participants results here (only regional averages and a few isolated representatives of populations not otherwise sampled) since they're too many to post with every run. I'll post the spreadsheet with Part III (Central Asia, Siberians and a few others), including all participant's results.

I have a few warnings to readers not familiar with the variability of ADMIXTURE results:
1) ADMIXTURE is a bit stretched figuring out patterns representing components as close as these, particularly over 30.000 or so SNPs. So small components aren't very reliable.
2) This run includes lots of extra populations and extra poles to my last "Basque5" vs "Chuvash5" one, so components, though related to those and named similarly, aren't the same and will differ.
3) In particular, the WMPC, WMPC+NC and WMPC+NWAf seem to vary at each other's expense a bit. WMPC+NC ended up being too much drawn to the Druze, and WMPC+NWAf too much to Tunisians. These samples may have multiple distant family links within them. I decided to keep these populations for the time being, but may remove them in a future run. So for some small elements in some populations, one of these components may be standing up for another one.
4) Any ancestry from regions not represented in the poles will tend to be pulled towards the "least inappropriate" pole. For example if some individuals have some East Asian ancestry it may appear as a Siberian segment.
5) My interpretations are obviously just conjecture, sometimes better argued than others.

You can read more extended interpretations of components in my previous post.
-WMPC: "West Mesopotamian Core", referred to before as "Western Wave". First wheat planting Neolithic colonization of the Mediterranean and Western Europe. I think they came from the Levant and Anatolia. I think it may correspond to Megalithic and Danubian archaeological horizons. In colder climes, this wave probably only occupied wheat-congenial regions, leaving less adequate ones to foragers. They're best represented today in Basques, Sardinians, and also at a lower lever in Western Europeans in general. Possibly with high R1b (and I?) Y-haplogroups
-NMPC: referred to before as the "eastern wave". Cold, poor-soil-adapted first Neolithic wave, maybe due to innovations such as winter-rye. Expanded North into the Steppe rivers from a homeland possibly in the Eastern Iranian Plateau, Caucasus range or Northern Mesopotamia. Later, after adaptation, it would have spread throughout cold and sandy soils in all of Europe, especially in the North, bypassing rich agricultural areas already inhabited at high densities by WMPC people. Possibly with high R1a Y-haplogroup levels. mit-haplogroups introduced by this wave into WMPC areas might explain why there's a "mit-DNA gap" between Danubian remains and modern Central Europeans. I would tend to identify the beginnings of NMPC expansion into Central and Western Europe with the Corded Ware culture. This may have been also the "melting pot" from where East Slavs began their long expansion towards the Pacific.
-WMPC+NC: synthesis of WMPC early intruders into Egypt and local Nile Core elements. Referred before as "Second Wave".
-WMPC+NWAfr: synthesis of Green-Sahara derived native North West Africans and WMPC. I think the expansion of this element into Iberia and beyond may have happen very early on (much earlier than the second wave in the East), at the time of initial WMPC colonization of the region via the Northern Mediterranean route.
-EMPC: East Mesopotamian Core. Patterns of NMPC and WMPC suggest to me this is a local, more eastern element that underwent expansion into the NMPC and WMPC homelands in ancient times, before the second wave from Egypt. I think a model of Neolithic developments generating higher surpluses and elites/specialists generally should coincide with a demographic expansion from the same region. That is any ancient people developing agricultural productivity high enough to enable them to live at much higher densities, and thus partially swamp out neighbouring related already agricultural peoples, must have produced enough food surpluses to allow relatively much larger elites/specialists and better social organization. Such secondary wave origin points should thus be identifiable archaeologically. The "Second Wave" I have identified with Egyptian Civilization (which begins at around 6000-5000 years ago, at the same time according to some studies as the early proto-Semitic expansion). Based also on ADMIXTURE patterns, I would tentatively relate the EMPC expansion with a Southern Mesopotamian homeland.
-All these components, except for the Siberian ones, derive I think from the ancient Near East. The Siberian ones correspond to perhaps ancient traces of European hunter-gatherers. I didn't include an Amerindian pole this time, since with multiple MPC components they tend to be identified and subsumed into the NMPC I think (since NMPC and forager residual segments tend to exist in the same populations-possibly due to NMPC late occupation of much of the colder, less fertile soil niche). More on that later.

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