Ancient DNA Rewrites the Stories of Buried Pompeii Victims

The Archaeological Park of Pompeii is a popular attraction for sightseers visiting the Gulf of Naples. I was fortunate to visit myself in 2023 and, like many tourists, was struck by the eerie famed body casts presented to the public in glass frames.

These plaster casts are all that remains of the victims of Mount Vesuvius’ infamous eruption in 79 AD, which killed the inhabitants of several nearby Roman towns. As hot ash compacted around the victims, it preserved their shape and features. While their soft tissue decayed over time, a cavity remained. During the 19^th century, excavators filled these cavities with plaster, creating casts of the victims. 

The casts are somewhat unsettling; many figures appear to be in the fetal position or clinging to others, presumed to be their loved ones.

In 2015, a portion of the casts underwent restoration. Scientists applied computed tomography scans and X-rays to explore whether any skeletal remains could be detected. Unfortunately, there were none. The project did reveal, however, that previous restoration efforts had made alterations to the casts. Some had rods inserted to support their structures, while others had been rearranged in a “creative” manner.

It became clear that modern interpretations of who these individuals were, where they came from and what happened to them, have been shaped not only by the archaeologists who first discovered and described them but also by those who had enhanced their features.

A collaboration of scientists including researchers from Harvard Medical School, the University of Florence and the Max Planck Institute (MPI) for Evolutionary Anthropology, questioned whether DNA extracted from the plaster casts could provide more accurate insights.

Over recent decades, significant progress has been made in the field of ancient DNA (aDNA) analysis. Scientists can now use sophisticated technologies to extract extremely degraded DNA and sequence it. In some cases, such studies confirm that events occurred exactly as they have been written in history books. In others, our understanding of human history is challenged and subsequently enriched.

Pompeii Archaeological Park. Credit: iStock. 

“Family” in The House of the Golden Bracelet were not family after all

Dr. Alissa Mittnik, group leader in the Department of Archaeogenetics at MPI, led the research group in successfully extracting DNA from 14 of the 86 casts undergoing restoration.  

Using this data, the genetic relationships, sex, ancestry and mobility of five individuals could be determined, which is published in Current Biology.

“The findings demonstrate the importance of integrating genetic analysis with archaeological and historical information to enrich or correct narratives constructed based on limited evidence,” said Mittnik.

That’s because the DNA data contradicts several long-standing narratives about the body casts of Pompeii. “For instance, one notable example is the discovery that an adult wearing a golden bracelet and holding a child, traditionally interpreted as a mother and child, were an unrelated adult male and child,” said Dr. David Reich, professor in the Department of Genetics at Harvard Medical School, a renowned researcher in the field of aDNA and co-author of the study.

“Similarly, a pair of individuals thought to be sisters, or mother and daughter, were found to include at least one genetic male. These findings challenge traditional gender and familial assumptions.”

A cosmopolitan Roman Empire, and a warning around misrepresentation

The Pompeiians analyzed in the study had different genetic backgrounds, with several descending from immigrants from the eastern Mediterranean. Studies of ancient genomes from the city of Rome tell a similar story, data that Reich said, “underscores the cosmopolitanism of the Roman Empire in this period.”

“Our findings have significant implications for the interpretation of archaeological data and the understanding of ancient societies,” Mittnik said. “They highlight the importance of integrating genetic data with archaeological and historical information to avoid misinterpretations based on modern assumptions.”

It’s important that aDNA analysis does not lead to the propagation of yet more misconceptions, Reich warned: “Instead of establishing new narratives that might also misrepresent these people’s experiences, the genetic results encourage reflection on the dangers of making up stories about gender and family relationships in past societies based on present-day expectations.”

The Director of Pompeii Park, Gabriel Zuchtriegel, explained that the site has been utilizing DNA analysis in its laboratory for many years. This includes the analysis of human and animal victims using additional methods such as isotopic analysis, diagnostics, geology, volcanology and reverse engineering. "All these elements together contribute to a comprehensive, updated interpretation of the archaeological findings. These efforts are turning Pompeii into a veritable incubator for the development of new methods, resources and scientific comparisons,” Zuchtriegel said.

“From this point of view, this study marks a true change in perspective, in which the site itself plays a central role in advancing archaeology and research."

Reference: Pilli E, Vai S, Moses VC, et al. Ancient DNA challenges prevailing interpretations of the Pompeii plaster casts. Curr Biol. 2024. doi: 10.1016/j.cub.2024.10.007