By studying the DNA of 37 13th- and 14th-century Jews buried in the German city of Erfurt, and comparing it to modern information about Ashkenazi genetics, a group of scientists have found some groundbreaking results. Among much else, they found that one woman had the same BRCA-1 gene—which can cause breast or ovarian cancer—carried by many Ashkenazi women today. Amanda Borschel-Dan reports:
According to research being hailed as “the largest ancient Jewish DNA study so far,” published Wednesday in the prestigious Cell science journal, by the 14th century Ashkenazi Jews had already received most of their main sources of genetic ancestry. When compared with the DNA markers of modern Ashkenazi Jews, there have been few changes to the genome in the centuries that have followed.
Through careful analysis, . . . an international team of over 30 interdisciplinary researchers found that the Jews of Erfut “were noticeably more genetically diverse than modern Ashkenazi Jews,” according to the co-author Shai Carmi. “An even closer inspection revealed that the Erfurt population was divided into two groups: one with more European ancestry compared to modern Ashkenazi Jews, and one with more Middle Eastern ancestry,” said Carmi. . . . [T]he results also indicated that the “founder event” or “bottleneck” that is evident in modern Ashkenazi Jewry’s DNA predated the establishment of the Erfut community, potentially by a millennium.
The central German city was a thriving Jewish center in the Middle Ages and boasts one of the oldest still-standing synagogues in Europe. The Jewish community settled there in the 11th century; a massacre decimated the community in 1349 but Jews lived in the area until a final expulsion in 1454. At this time, a granary was constructed on top of the graveyard, sealing in the remains of thousands of Jews.
Read more on Times of Israel: https://www.timesofisrael.com/largest-study-of-ancient-dna-shows-medieval-ashkenazi-jewry-was-surprisingly-diverse/