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If you haven't already heard, a halakhic loophole has allowed researchers to take DNA samples from 14th Century Jewish remains in Erfurt (https://twitter.com/ShaiCarmi/status/1526850050772590592).
According to a simple model I've formulated, the three Erfurt clusters represent: 1) Erfurt1a: older N. European Ashkenazim (perhaps descendants of the first wave of Jewish migration to the area circa 800-1100 CE); note that modern German Ashkenazim in the same cluster area as Erfurt1a, 2) Erfurt1b: a wave of migrants from Spain (many Jews were fleeing from Sepharad as early as the Granada Massacre of 1066 and after the Almohads conquered Sepharad circa 1121 until about 1269); on the scatter, Erfurt1b clusters nearby to modern Sephardim; 3) Erfurt2: this is the one that I find most fascinating because it introduces a new aspect to the history which I had not thought about until now: a wave of Jewish migrants coming from the Southern Italian Peninsula seem to have acquired Avar-Longobardic genes since the time when the Longobards and their Avar allies invaded those territories. I am not too clear on the exact historical exigencies that brought this group to N. Europe, nor when the migration may have occurred, but I believe that the data support a period of Jewish-Avar hybridization in Southern Italy (and possibly N. Italy as well) from about 650 CE until 1000 CE. Could the Avars be the answer to the riddle of Central Asian genes in the Ashkenazic population? We shall see....
I really don’t know too much about the Avars, besides their Uralic linguistic affinities, but I suppose they could be the vector bringing the unusual East Asian genes into the Erfurt samples, via the Longobards in S. Central Italy. According to this recent study: https://doi.org/10.1101/2022.01.19.476915, the Avars received Xiongnu genes before coming into the Pannonian Plain. According to Amorim, et al, (DOI: 10.1038/s41467-018-06024-4) the Avars became allies of the Longobards (the sample SZ1 which is on the scatter is a later burial from a Longobard cemetery in the Pannonian area, reported in this paper). Amorim goes on to say: “the Longobard duchies of Spoleto and Benevento ruled much of the inland areas of the [Italian] peninsula…” This would have been the time of the Lombard princes Pandulf and Landulf. It is known that Benevento was a Jewish population center during this period (https://en.wikipedia.org/wiki/Benevento#Jewish_history), so there appears to have been an opportunity for introgression.
I am not sure what to make of the Erfurt3s: I14897 appears to be a Sephardic-S. Italian hybrid. I13867 could be a Original Ashknenazi-S. Italian hybrid.
An interesting aspect of this model is that the Erfurt average point clusters with modern Eastern European Ashkenazim which suggests to me that we see in Erfurt, the ingredients which were later to become the Eastern Ashkenazim population.
There is much to be unraveled here and I am curious to see what models others make of these data.