Krishna Veeramah, associate professor in the Department of Ecology and Evolution at Stony Brook University’s College of Arts and Sciences, is leading an international team of researchers in a new study of ancient DNA that provides insight into the development and social structures of European rural communities following the fall of the Roman Empire.
The findings, published in a paper in the Proceedings of the National Academy of Sciences (PNAS), suggest that early medieval elites, or those of higher social status, were initially made up of multiple families with distinct genetic ancestries. Over time, these families intermarried and local communities integrated genetically diverse newcomers from various social and cultural backgrounds.
The research team combined paleogenomic, archaeological, and isotopic data to shed light on the community that used a cemetery in Collegno, Italy, as a burial site during the 6th to 8th centuries CE. Researchers sequenced and analyzed the genomes of 28 individuals from the cemetery and incorporated data from 24 previously published genomes. They also studied individuals’ patterns of social mobility, burial patterns, and diet.
“When the Roman Empire collapsed, we did not really know much about how new communities formed, yet many of these communities would go on to be the basis for modern European countries,” explained Veeramah. “Our study reveals that these elites were genetically surprisingly diverse, and in the process of creating new European communities in the medieval era, families with diverse genetic ancestry would come together to form ruling groups.”
“In 2018, our team published a paper that demonstrated genomic and cultural similarities between Collegno and Szólád, a village in modern Hungary that showed a significant correspondence between individuals with a northern European ancestry in both,” said Patrick Geary of the Institute for Advanced Study. “Our new study follows the transformation of this Italian community over a century and shows how new groups moved into and merged with existing inhabitants.”
The researchers discovered that the Collegno community was initially established by and organized around a network of closely related individuals, likely from several elite families. But over time, they evolved into a single extended lineage spanning at least five generations.
Veeramah and colleagues believe individuals from this lineage had a higher ranking in society based on their richer diets and heavily detailed items they were buried with, such as weapons and elaborate belts.
The findings also show that while the Collegno community was initially established by these elite families—many from northern Europe—the community later incorporated individuals from other origins and genetic backgrounds into it.