Ancient DNA Reveals 5,500-Year-Old Plague in Siberia

New evidence from ancient DNA reveals that the plague, caused by the bacterium Yersinia pestis, was devastating human populations in Siberia as far back as 5,500 years ago. This predates the Black Death by millennia and challenges the notion that plague epidemics were solely a phenomenon of densely populated urban centers or relied on flea vectors in the same way modern strains do. Researchers analyzed DNA from human remains found at sites across Eurasia, identifying the bacterium in multiple individuals from a single Siberian burial site dating to the Neolithic period.

These prehistoric strains of Yersinia pestis were particularly virulent, carrying a genetic factor (the ymt gene) capable of provoking severe immune reactions in infected individuals. This insight comes from a comprehensive genomic study published in the journal Nature, which sequenced multiple ancient bacterial genomes.

Implications for understanding pandemics

The discovery of plague in hunter-gatherer communities highlights its enduring capacity to cause pandemics, even in sparse populations. The ancient strains’ specific genetic makeup, particularly the ymt gene responsible for increased toxicity, provides a critical data point. For example, analyses of these 5,500-year-old genomes show key differences from later strains, such as the absence of some genes typically associated with flea-borne transmission.

By understanding the genetic toolkit of ancient pathogens and how they impacted human health over millennia, individuals gain insights into the deep history of their immune system and the ongoing battle against infectious diseases. This knowledge empowers a more informed approach to personal and public health preparedness.