Saturday, December 30, 2023

Unexpected ancient DNA results from pre-Islamic Bahrain.

Unexpected ancient DNA results from pre-Islamic Bahrain. They are different from modern day Arabs living there and plot close to ancient Mesopotamian samples from Iraq. On the PCA they plot just in the vicinity of ancient samples from South Caucasus, North-West Iran and North Iraq LBA. In this group we use the term "Central farmers" for this type of ancestry.

Assuming those samples were not some kind random migrants then we can imagine that most of Mesopotamia was like this prior the arrival of Arabs.
This data gives us a hint what we can expect from more ancient inhabitants of Mesopotamia. Sumerians and Akkadians.
The island Bahrain is usually connected with the land Dilmun in ancient Mesopotamian texts. Although other opinions also exist on the location of Dilmun.
Below are some excerpts from the paper.

Lastly, we evaluate the ancestry of Bahrain Tylos individuals in a context of Near Eastern variation by estimating ancestry proportions using a previously published 12 three-way model with TUR_Pınarbaşı_EpiP, ISR_Natufian_EpiP and CHG as sources in a set of relevant ancient groups which can also be modelled in this way (Figure 3C) 12. In this model, the Bahrain_Tylos samples present similar ancestry proportions to AZE_ChL, Mesopotamia_PPN and IRQ_Nemrik9_LBA, IRN_Dinkha_Tepe_A, LBN_IA and to ARM_Aknashen_N. Accordingly, rank=0 qpAdm models show that Tylos-period Bahrainis form a clade with several of these ancient groups (p≥0.01; Table S6), suggesting that similar sources have contributed to their ancestry.
...
Tylos-Period Bahrainis are genetically closer to present-day Levantine populations than to present-day Arabians
Regarding affinities with present-day populations, the temporally aware model-based clustering analysis (Figure 1B) suggests that Tylos period Bahrain samples are more similar to present-day Levantine groups than to present-day Arabians or South Asians,
...
In order to gain further insights into the relationship of Tylos to present-day populations from the Arabian Peninsula and the Levant, we tested if the Bahraini samples form a clade with any modern population in our dataset using a set of reference populations (as outgroups) that can differentiate the different ancestries in the Near East. We found that Iraqis, Assyrians and Jewish groups from Iran, Georgia and Iraq could derive all their ancestries from Tylos-period Bahrainis (Table S8). Arabians such as Saudis, Emiratis and Yemenis have, in addition to ancestry from Tylos-period Bahrain, ancestry from East Africa, while Levantines such as Druze and Lebanese have additional Southeast European ancestry (Table S9)

See also



Tuesday, December 5, 2023

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 its 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. https://www.yfull.com/tree/G-M377/
  • 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 years ago so it's probably represented an old migration of KA to Anatolia and a secondary expansion in Iron Age. https://www.yfull.com/tree/G-Y37100/
  • 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. https://www.yfull.com/tree/G-FT36238/