Ancient DNA from medieval Germany tells origin story of Ashkenazi Jews
Excavating ancient DNA from teeth, an international group of scientists peered into the lives of a once thriving medieval Ashkenazi Jewish community in Erfurt, Germany. The findings, shared today in the journal Cell, show ...
About half of Jews today are identified as Ashkenazi, meaning that they originate from Jews living in Central or Eastern Europe. The term was initially used to define a distinct cultural group of Jews who settled in the 10th century in Germany's Rhineland. Despite much speculation, many gaps exist in our understanding of their origins and demographic upheavals during the second millennium.
"Today, if you compare Ashkenazi Jews from the United States and Israel, they're very similar genetically, almost like the same population regardless of where they live," shared geneticist and co-author Professor Shai Carmi of the Hebrew University of Jerusalem (HU). But unlike today's genetic uniformity, it turns out that the community was more diverse 600 years ago.
Digging into the ancient DNA of 33 Ashkenazi Jews from medieval Erfurt, the team discovered that the community can be categorized into what seems like two groups. One relates more to individuals from Middle Eastern populations and the other to European populations, possibly including migrants to Erfurt from the East. The findings suggest that there were at least two genetically distinct groups in medieval Erfurt. However, that genetic variability no longer exists in modern Ashkenazi Jews.
The Erfurt medieval Jewish community existed between the 11th and 15th centuries, with a short gap following a 1349 massacre. At times, it was a thriving community and one of the largest in Germany. Following the expulsion of all Jews in 1454, the city built a granary on top of the Jewish cemetery. In 2013, when the granary stood empty, the city permitted its conversion into a parking lot. This required additional construction and an archaeological rescue excavation.
This image shows the construction of an access ramp to convert a 15th century granary in Erfurt, Germany, into a parking garage. A rescue excavation uncovered graves of the Jewish cemetery underneath, from which the researchers collected detached teeth for an ancient DNA analysis. The skeletons were then reburied in the 19th century Jewish cemetery. Credit: Waldman et al./Cell
This image shows a tooth collected from the medieval Jewish cemetery in Erfurt, Germany. Researchers collected 38 teeth from the excavation site, from which they extracted ancient DNA from 33 individuals. Credit: David Reich ancient DNA laboratory / Harvard Medical School
While converting the 15th century granary (large brown building) into a parking garage in Erfurt, Germany, graves from the Jewish cemetery underneath were uncovered. After a rescue excavation to move the remains to a 19th century Jewish cemetery nearby, an access ramp was put in place (circular structure on the right in this image). Credit: Shai Carmi, The Hebrew University of Jerusalem