Researchers have identified the oldest known evidence of the plague, dating back nearly 5,500 years. This timeline is about 200 years earlier than previously thought. The disease has afflicted humans for millennia, with a significant impact in the 14th century during the Black Death, which decimated a large part of Europe’s population. Although rare, the plague still exists today and is treatable with antibiotics.
Eske Willerslev, an evolutionary geneticist at the University of Copenhagen, emphasized the importance of understanding the plague’s history to comprehend our own. Willerslev and other researchers examined cemeteries near Lake Baikal in Siberia, searching for traces of the bacteria that cause the plague. They discovered plague DNA in the teeth of 18 ancient hunter-gatherers. Carbon dating of the bones indicated two outbreaks, with the earliest cases emerging approximately 5,500 years ago.
The team found that prehistoric plague developed in stages and infected several small families. It likely spread through marmots, large native rodents, when people consumed their raw organs or handled infected skins during butchering. The disease also transmitted from person to person through coughing and sneezing, according to the authors.
Many of those who died were children aged between 8 and 11. Three girls were buried side by side, with two probably being cousins. An aunt and her nephew were found together, while her niece was in a separate communal grave. Ruairidh Macleod, a co-author from the University of Oxford, noted that those who buried these individuals knew who they were, adding a human element to the scientific work. Children may have been more vulnerable due to weaker immune systems, researchers suggested.
The presence of multiple victims suggests prehistoric plague was capable of causing both individual cases and outbreaks, stated Aida Andrades Valtueña, a geneticist from the Max Planck Institute for Evolutionary Anthropology, who was not involved in the study.
Researchers found that this ancient form of the plague evolved long before the bubonic plague responsible for the medieval Black Death. However, there is evidence that earlier plagues were equally deadly, affecting not just crowded cities but also small nomadic hunter-gatherer groups.
Andrades Valtueña noted that understanding the bacteria’s evolutionary steps toward becoming the deadly pathogen known today could provide insights into how pathogens might emerge in the future.
The Associated Press’s Department of Health and Science, supported by the Howard Hughes Medical Institute’s Science Education Department and the Robert Wood Johnson Foundation, produced this content. AP is solely responsible for all content.
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