tiistai 28. tammikuuta 2014

A little more about the North Asian admixture in Northeast Europe

In my previous text Admix analyses – absolutes?   I examined rules of admixture analyses and tested corresponding  algorithms.  I proved that the formal admix analysis  based on the commonly used MCMC algorithm gives only relative results and results vary depending on used “genetic edges”..  In my example the Siberian admix commonly shown among Northeast Europeans was depending on the most western samples used in the analysis.  So the Siberian shown in most analyses was the common affinity between NE-Europeans and Siberians calculated from the difference of genetic affinity between NE-Europeans and the most western population.  The result didn't indicate real genetic flow directions.  Because genes are strongly related to the geography the result varies strongly.  Using even purest Siberians, NE-Europeans and Lithuanians to find out the Siberian admix in Northeast Europe gives different result than using same Siberians, NE-Europeans and Sardinians (or French samples).  This was the background.

Concerning this same issue I found an interesting new view from the latest monthly magazine of DnaTribes.   DnaTribes was inspired by the famous  Mal’ta  boy from  ancient Siberia.  Mal’ta boy has been a headline in genetic archaeology because his genes reveal that ancient Siberians where a connection between Europeans and Native Americans without East Asian genetic affinity.  People with similar genetic structure lived in Siberia and moved to Europe and America before the recent Siberians.   It is likely that they mixed later in Siberia with people from East Asia forming recent Siberian populations.   So Mal’ta boy’s genes live in America, Europe (mostly in Nortern Europe), but very likely also in Siberia.   DnaTribes has tested this problematic.  And what did they find?  They found that if they remove local genes in every geographic location and look only for foreign genes then Siberian populations have around 3% of Finnic genes.   It is hard to say the time when these Finnic genes travelled to Siberia, or are they remains of Mal’ta boy’s genes, but this is a fully coherent result with my admix analyses indicating Northeast European genes in Siberia at the level around 3-8%, even after purifying Siberian samples from outliers. 

Link to DnaTribes’ article.

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