Ancient DNA rewrites the stories of those preserved at Pompeii

Researchers from the University of Florence, Harvard University and the Max Planck Institute for Evolutionary Anthropology have used ancient DNA to challenge long-held assumptions about the inhabitants of the city of Pompeii, reporting their findings in the journal Current Biology.

In 79 AD, the active volcano known as Mount Vesuvius experienced one of its most significant eruptions, burying the Roman city of Pompeii — as well as the nearby town of Herculaneum — under a thick layer of small stones and ash known as lapilli. Many of Pompeii’s inhabitants lost their lives as their homes collapsed under the weight of the lapilli raining down from many kilometres above, while those who survived the initial phase of the eruption eventually succumbed to dangerous pyroclastic flows — fast-moving streams of hot gas and volcanic matter that instantly enveloped them in a solid layer of ash, effectively preserving their bodies and features.

Although the soft tissue decayed, the outlines of the bodies remained and were recovered by excavators centuries later by filling the cavities with plaster — which led to certain assumptions about the victims’ sex and kinship based on their physical appearance and the positioning of the casts. But the research team, who had heard the stories of Pompeii, realised that ancient DNA and strontium isotopes used to date samples could help them to better understand the diversity and origins of Pompeii’s residents.

The team managed to generate genome-wide ancient DNA and strontium isotopic data from highly fragmented skeletal remains that were embedded in the plaster casts, focusing on 14 casts that were undergoing restoration. This allowed them to determine the genetic relationships, sex, ancestry and mobility of five individuals. Interestingly, this DNA evidence shows that individuals’ sexes and family relationships don’t match traditional interpretations that had been formulated largely from modern-day assumptions.

“The scientific data we provide do not always align with common assumptions,” said David Reich of Harvard University. “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. Similarly, a pair of individuals thought to be sisters, or mother and daughter, were found to include at least one genetic male.”

“The findings challenge enduring notions such as the association of jewellery with femininity or the interpretation of physical proximity as evidence of familial relationships,” noted Professor David Caramelli, from the University of Florence.

Group of casts from the House of the Golden Bracelet, created in 1974. Image courtesy of the Archaeological Park of Pompeii.

The genetic data also provided information about the ancestry of the Pompeiians, who had different genomic backgrounds. They primarily descended from recent immigrants from the eastern Mediterranean — a finding which highlights the cosmopolitan nature of the Roman Empire, the researchers said.

“Our findings have significant implications for the interpretation of archaeological data and the understanding of ancient societies,” said Alissa Mittnik, from the Max Planck Institute. “They highlight the importance of integrating genetic data with archaeological and historical information to avoid misinterpretations based on modern assumptions. This study also underscores the diverse and cosmopolitan nature of Pompeii’s population, reflecting broader patterns of mobility and cultural exchange in the Roman Empire.”

“It is also likely that the use of these casts for narration purposes could have led to past restorers modifying their postures and placements,” Caramelli added. “The combined use of genetic data and other bioarchaeological methods provides us with the chance to better comprehend the lives and habits of the victims of the Vesuvius eruption.”

Top image caption: Casts from the House of the Cryptoporticus, created in 1914. Image courtesy of the Archaeological Park of Pompeii.