About 5,500-year-old plague found in human remains: Study
News Desk
For centuries, historians and scientists believed that devastating plague outbreaks emerged only after humans began farming, building large settlements and living in close proximity to one another. A groundbreaking new study is now challenging that assumption.
Researchers have uncovered evidence of what appears to be the world’s oldest known plague epidemic, dating back approximately 5,500 years, among small hunter-gatherer communities living around Lake Baikal in Siberia.
The discovery not only pushes back the timeline of plague in human history but also suggests that the disease was capable of causing deadly outbreaks long before the rise of cities and agriculture.
The findings, published in the scientific journal’ ‘Nature’, indicate that the epidemic disproportionately affected children and young people, leaving a profound impact on ancient communities that relied on hunting and food gathering for survival.
Traces of a Deadly Disease
An international team of researchers analyzed DNA extracted from human remains recovered from four ancient cemeteries near Lake Baikal. Of the 46 individuals examined, 18 carried traces of ‘Yersinia pestis’, the bacterium responsible for plague.
According to the researchers, this represents the oldest evidence of plague ever discovered.
The region’s inhabitants lived in relatively small and remote groups. Their diet consisted mainly of deer, moose, fish, seals and marmots, a large rodent species common in the area. Scientists believe these marmots likely served as the original hosts of the disease, transmitting the pathogen to humans.
Rewriting the History of Plague
The discovery is reshaping scientific understanding of how and when plague emerged as a threat to human populations.
According to senior study author Eske Willerslev, a geneticist affiliated with the University of Copenhagen and the University of Cambridge, the findings challenge long-held assumptions about the disease’s origins and its role in early human history.
Plague has been one of the most devastating pathogens ever encountered by humanity, Willerslev noted, and the new evidence suggests it was affecting human communities much earlier than previously believed.
Before this discovery, the oldest known evidence of plague came from present-day Latvia and dated back approximately 5,000 to 5,300 years. The Siberian findings predate those remains and indicate that the disease had already been circulating centuries earlier.
Lead author Ruairidh MacLeod, an evolutionary geneticist at the University of Oxford, explained that plague primarily survives among rodents and other small animals but has repeatedly crossed into human populations throughout history, often with catastrophic consequences.
A Disease That Changed Civilizations
Plague has left an unmistakable mark on human history.
Among its most infamous outbreaks were the Plague of Justinian in the sixth century and the Black Death of the fourteenth century. The Black Death alone wiped out a substantial portion of Europe’s population and remains one of the deadliest pandemics ever recorded.
During those later epidemics, infected fleas carried by rats played a crucial role in transmitting the disease to humans.
Scientists had long assumed that such devastating outbreaks required densely populated settlements created by agriculture. They also believed that earlier forms of plague were comparatively mild.
The Lake Baikal evidence, however, tells a different story. The findings suggest that severe and deadly plague epidemics could occur even among small, scattered hunter-gatherer populations.
Clues Hidden in Ancient Teeth
To investigate the epidemic, researchers extracted genetic material from the teeth of infected individuals buried in the cemeteries.
Analysis revealed that the ancient plague strain occupied an intermediate stage in the bacterium’s evolution. It was already capable of causing severe illness but lacked some of the characteristics associated with later global pandemics.
Notably, the ancient strain did not possess a gene believed to be essential for efficient flea-borne transmission. Despite this limitation, researchers discovered a unique genetic feature that may have triggered severe inflammation and dangerous complications, particularly in children.
This finding may help explain one of the most striking patterns observed in the cemeteries.
Children Were the Most Vulnerable
Many of the individuals buried at the sites were children. In several cases, siblings were laid to rest together in the same grave, suggesting that multiple members of the same family died during the outbreak.
Researchers found that children between the ages of eight and 12 appeared to face the highest risk of death from the disease. This mortality pattern differs significantly from other ancient sites in the region where no evidence of plague has been identified.
The concentration of child victims points to a particularly severe epidemic that affected entire families and communities.
How the Disease May Have Spread
Scientists believe some people may have contracted the disease while hunting infected marmots or by consuming improperly cooked marmot meat.
Once introduced into human populations, the disease may have spread through close personal contact or respiratory droplets produced during coughing.
Although researchers continue to investigate the exact transmission pathways, the evidence suggests the epidemic moved through communities with devastating consequences.
Signs of Loss and Survival
The cemeteries provide more than evidence of disease; they also offer a glimpse into how ancient people responded to tragedy.
Mass burials and graves containing multiple family members indicate that the epidemic claimed numerous lives within a short period. Yet the careful placement of bodies suggests that survivors remained present to identify and bury their loved ones.
Researchers say these burial practices demonstrate social bonds and communal care even in the face of widespread death.
While the plague inflicted a heavy toll on the hunter-gatherer groups living around Lake Baikal 5,500 years ago, the archaeological record shows that communities endured, mourned their dead and continued their lives despite the catastrophe.
The study provides one of the clearest windows yet into the earliest known plague epidemic and offers valuable insights into how infectious diseases shaped human societies long before the rise of civilization.
