Hunter-gatherers in Siberia died of a plague outbreak 5,500 years ago

A groundbreaking study has revealed that a devastating plague outbreak struck hunter-gatherer communities in southeastern Siberia approximately 5,500 years ago, resulting in numerous fatalities. Researchers from the University of Oxford, led by ancient DNA specialist Ruairidh Macleod, successfully sequenced the DNA of the Yersinia pestis bacteria from the teeth of victims discovered in four ancient cemeteries near Lake Baikal. This finding represents the earliest known instance of plague, linked to the oldest strain of Y. pestis ever analyzed. Previously, scientists studying the evolution of the plague held two main theories. One suggested that early strains lacked the genetic makeup necessary for high lethality, while another posited that the disease emerged with the advent of agriculture, as humans began living in close quarters with domesticated animals and rodents. However, the evidence from the Ust’-Ida I cemetery challenges these long-held beliefs. Macleod and his team concluded that significant outbreaks of plague occurred among prehistoric hunter-gatherers, long before the rise of Neolithic farming communities. This revelation contradicts the notion that the transition to settled agricultural life was a primary factor in the spread of plague, which had been thought to thrive in densely populated settlements. Macleod emphasized the implications of their research, stating, "Much of the accepted theory around the epidemiology of disease in the past is that this kind of thing shouldn’t occur in hunter-gatherers because they are always moving and living in small groups. The prevailing idea has been that infectious diseases cannot take root and devastate entire communities in such a dynamic lifestyle." This new understanding prompts a reevaluation of how we view the history and spread of infectious diseases across ancient human populations.