Plague DNA has been found dating back 4,000 years, making it Britain’s oldest evidence of the disease.
The researchers’ findings could help understand which genes are “important for the transmission of infectious diseases,” one of them said.
Scientists at the Francis Crick Institute (FCI) have found three cases of Yersinia pestis – the bacterium that causes plague – in human remains.
Two were found in a mass burial at Charterhouse Warren, Somerset, and another was found in a ring stele in Livingstone, Cumbria.
Working with local groups and the University of Oxford, the team collected a small number of bone samples from 34 individuals at the two sites.
They then drill into the tooth and extract the pulp, which traps the DNA remnants of infectious diseases.
It was “incredible” to be able to detect ancient pathogens in “degraded samples” from so long ago, said author Pooja Swali, a doctoral student at FCI.
She added: “These genomes can tell us about the spread and evolutionary changes of pathogens in the past, and hopefully help us understand which genes may be important for the spread of infectious diseases.
“We saw Yersinia pestis lineages, including the genomes in this study, lose genes over time, a pattern that emerged in subsequent epidemics caused by the same pathogen.”
Previously, plague was found in several peoples in Eurasia between 5,000 and 2,500 years ago (BP).
The researchers said the UK had never seen anything like it during this period.
Its wide geographic distribution is thought to indicate that it spreads easily.
“This study is a new piece of the puzzle in our understanding of the ancient genomic record of pathogens and humans and how we co-evolved,” said Pontus Skoglund, group leader of the FCI’s Ancient Genomics Laboratory.
“Future studies will learn more about how our genomes have responded to such diseases in the past, and the evolutionary arms race with the pathogens themselves, which could help us understand the impact of diseases now or in the future.”
The findings were published in Nature Communications.