The ancient Italian city of Pompeii was destroyed by an eruption of Mt Vesuvius in 79 AD. More than 2,000 people died as a direct consequence of the eruption, and the city was buried under four to six metres of volcanic ash and pumice and seemingly lost to time.
Pompeii was rediscovered in 1748, and human remains have since been excavated from the archaeological dig site. Now, for the first time, the genome of one of these individuals has been sequenced in full, according to a new study in Scientific Reports.
Scientists have examined the skeletal remains of two humans from the city’s Casa del Fabbro (House of the Craftsman) and extracted their ancient DNA. One set of remains belonged to a male, aged between 35 and 40 years old at the time of his death, and the other belonged to a female over 50 years of age.
Due to the position and orientation of the human remains, the authors suggest they probably died instantly due to the approach of the high-temperature volcanic ash cloud.
They team analysed the ancient DNA extracted from the petrous bone – a wedge-shaped mass of bone within the cranial cavity – and while there were gaps in the sequences recovered from the female’s remains, they were able to sequence the entire genome of the male.
Before now, only short stretches of mitochondrial DNA from human and animal remains had been sequenced from Pompeii, since exposure to high temperatures reduces the quality and quantity of recoverable DNA.
But the authors speculate that the pyroclastic materials – the fast-moving flow of solidified lava pieces, volcanic ash and hot gases – that covered the remains may have also shielded them from environmental factors, such as atmospheric oxygen, that degrade DNA over the years.
They compared the male individual’s DNA with DNA from 1,030 other ancient humans (from Upper Palaeolithic to Medieval periods) and 471 modern western Eurasian individuals and found that his DNA shared the most similarities with modern central Italians and those who lived in Italy during the Roman Imperial age (27 BCE to 476 AD), as you might expect.
Interestingly, his mitochondrial DNA and Y chromosome DNA, in particular, also contains groups of genes that are commonly found in people from the island of Sardinia, but not among other individuals who lived in Italy during the Roman Imperial age.
This suggests there may have been high levels of genetic diversity across the Italian Peninsula during this time.
Further analysis also identified lesions in one of his vertebra, as well as DNA sequences commonly found in the group of bacteria to which Mycobacterium tuberculosis – the pathogen that causes tuberculosis – belongs.
This suggests that the man may have been affected by spinal tuberculosis (Pott’s disease) prior to his death.
According to the researchers, these findings “provide a foundation to promote an intensive analysis of well-preserved Pompeiian individuals” to gain more insight into the genetic history and lives of this population.
Imma Perfetto is a science journalist at Cosmos. She has a Bachelor of Science with Honours in Science Communication from the University of Adelaide.
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