In a groundbreaking discovery, scientists have uncovered DNA evidence of a 4,000-year-old plague in Britain. This finding represents the oldest known cases of plague in the country to date. By analyzing ancient DNA, researchers have gained invaluable insights into the presence and impact of this ancient disease on the population of ancient Britain.
The identification of plague DNA from such an early time period provides valuable clues about the historical spread and evolution of this devastating infectious disease. This discovery not only deepens our understanding of ancient epidemics but also sheds light on the health challenges faced by ancient societies and their interactions with contagious diseases.
Scientists studied skeletal samples from 34 individuals at two sites to find traces of Yersinia pestis, the bacterium that caused the plague. By examining dental pulp from teeth, they discovered three cases of Yersinia pestis in two children and one woman. Radiocarbon dating suggested that these individuals lived during the same time period.
Interestingly, the presence of Yersinia pestis in Britain during that era was previously unknown. However, it had been found in other parts of Eurasia.
This suggests that the specific strain of the plague discovered, the LNBA lineage, may have spread widely and easily. The study was published in Nature Communications by Pooja Swali in 2023.
The LNBA lineage of the Yersinia pestis bacterium is believed to have been introduced to Central and Western Europe around 4,800 years ago by migrating humans. This new research suggests that the same strain reached Britain as well. By analyzing the genome sequences, scientists found that this particular strain closely resembled those in Eurasia during the same period.
Interestingly, the genomes of the identified strains lacked yapC and yet genes, typically present in later strains associated with flea transmission.
This suggests that this specific strain may have been transmitted differently, unlike the strain responsible for the Black Death. The Bronze Age, characterized by using bronze artifacts, began around 3200 BC in Europe. In Britain, the Bronze Age coincided with the arrival of people approximately 4,400 years ago, as identified by their distinctive Beaker pottery.
Due to the quick degradation of pathogenic DNA in incomplete or eroded samples, it is possible that other individuals at the burial sites were also infected with the same plague strain. The Charterhouse Warren site is unique because it differs from other funeral sites of that time period.
The individuals buried there seem to have died from trauma, leading researchers to believe that the mass burial may not result from a plague outbreak but rather that the individuals were infected at their death.
Pooja Swali, first author and Ph.D. student at the Crick said, “The ability to detect ancient pathogens from degraded samples from thousands of years ago is incredible. These genomes can inform us of the spread and evolutionary changes of pathogens in the past and hopefully help us understand which genes may be important in the spread of infectious diseases. This Yersinia pestis lineage, including genomes from this study, loses genes over time, a pattern that has emerged with later epidemics caused by the same pathogen.”
Pontus Skoglund, group leader of the Ancient Genomics Laboratory at the Crick, said, “This research is a new piece of the puzzle in our understanding of the ancient genomic record of pathogens and humans and how we co-evolved.
The researcher said, “We understand the huge impact of many historical plague outbreaks, such as the Black Death, on human societies and health, but ancient DNA can document infectious disease much further into the past. Future research will do more to understand how our genomes responded to such diseases in the past and the evolutionary arms race with the pathogens themselves. This can help us understand the impact of diseases in the present or future.”
This discovery could help scientists better understand the plague’s evolution and the factors contributing to its spread. It could also help to develop new strategies for preventing and treating the disease.