Tuesday, December 5, 2023

The genetic story of G2b

 The genetic story of G2b

Thanks to Hovann Simonian we have a number of modern Armenian G2b on Yfull. Coupled with ancient DNA we can now have a better idea about the history of G2b.
G2b unlike his "brother" G2a was a minor Fertile Crescent lineage that formed in more eastern regions than Anatolia. It was absent in Anatolian and European Neolithic sites. The finding of 9200 year old G2b in Zagros, West Iran confirms it's more eastern homeland. (See the map). G2b have three important branches, having an old common ancestor, who lived 20.000 years ago. He lived even prior farming was invented. Those three branches had different stories.
G2b1-M377 - This branch apparently was a Copper Age lineage. It is popular in Ashkenazi Jews and Pashtos in Afghanistan. Both are result of Current Era founder effects. The common ancestor of Jewish and Pashto clusters lived some 5500 years ago, so it is hard to say it's real origin given the absence of aDNA from this branch. An Armenian from Syunik is present on basal position in this branch having a 8700 year old common ancestor.
G2b2a-Z8022 - It was found in Wezmeh cave in West Iran in a Neolithic period. Later another sample was found in Kaps (Shirak) from Kura-Araxes period (more than 5000 years ago). And finally a number of G2b2a were found from Teishebaini (Karmir Blur) in later LBA and Iron Age period. Etiuni people had preserved some Y dna from Kura-Araxes culture so the G2b2a was one of them. In most likelihood G2b2a was present in South Caucasus since the Neolithic era. See the second picture. An Armenian from Urfa and a number of Turks are from this branch. Their common ancestor lived 3200 year ago so it's probably represent an old migration of KA to Anatolia and a secondary expansion in Iron Age.
G2b2b-FT36238 - There are no ancient DNA from this branch. There is a young 2600 year old branch which apparently is an Armenian branch given the presence of Armenians there. A very distant 19000 years parallel branch is found in Kuwait.

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