A study in Nature has uncovered evidence of deadly plague outbreaks among Siberian hunter-gatherers 5,500 years ago, challenging the long-held assumption that the disease required crowded urban settings to spread. The findings, based on ancient DNA analysis, indicate that Yersinia pestis was already capable of causing lethal epidemics in small, mobile communities.
This discovery rewrites the history of one of humanity's most feared pathogens. Until now, plague was primarily associated with the medieval Black Death and later pandemics that thrived in dense populations. The study suggests the bacterium's virulence evolved much earlier than previously believed.
The research analyzed skeletal remains from the Lake Baikal region, where hunter-gatherer groups lived in small bands. Genetic sequencing revealed the presence of Yersinia pestis DNA, confirming that these ancient populations experienced fatal outbreaks despite their dispersed lifestyle and lack of agriculture.
The findings imply that plague's lethality predates the Neolithic Revolution, meaning early humans faced this threat in far different social conditions than those seen in historical records. This could reshape understanding of how pathogens adapt to human hosts over millennia.
Some experts caution that the small sample size and geographic isolation of these ancient groups may limit how broadly these results can be applied to other prehistoric populations.