On this very special episode of Unsupervised Learning I talk to three guests, Josh Lipson, Aric Lomes and Leo Cooper, about their contribution to a new paper, Genome-wide data from medieval German Jews show that the Ashkenazi founder event pre-dated the 14th century. Given that a month earlier, Genomes from a medieval mass burial show Ashkenazi-associated hereditary diseases pre-date the 12th century was also published, 2022 has seen a massive growth in our ancient-DNA-informed understanding of the origins of the Ashkenazim. Last year Lipson and I talked about the genetics of the Jews in what would prove the waning days of the pre-ancient-DNA era for this population. This was in the wake of my post, Ashkenazi Jewish genetics: a match made in the Mediterranean.

The broad outlines of earlier work have not been overturned with these papers, but Lipson, Lomes and Cooper shed light on numerous details relating to the relationship of the early Ashkenazim and the Sephardim of Spain, the division of the early Jews of Germany into two genetic clusters, and the possible relationship of the Ashkenazim to groups further to the east, including the Khazars. The discussion also touches on the nature of the bottleneck that the Ashkenazim weathered, their possible origins among southern Italians, and the deep roots of many of the recessive diseases that they carry today.