Ancient DNA from cemeteries in southeast Siberia has revealed previously unknown strains of plague that had a deadly impact on hunter-gatherer communities 5,500 years ago.
Discovery of Ancient Plague Strains
The early plague strains, detailed in a new study published in the journal Nature, may be the oldest known evidence of the disease in humans. Plague is caused by the bacterium Yersinia pestis and has led to some of the most devastating disease outbreaks in human history.
Researchers came across the ancient strain while trying to solve another puzzle in the remains of hunter-gatherers buried in cemeteries of the Lake Baikal region. Two of the largest cemeteries contained an unusually large number of children and young adolescents whose remains lacked any trauma or apparent cause of death.
An analysis of ancient DNA within the remains revealed the unexpected presence of plague bacteria in 18 of 46 individuals from the small, mobile communities — as well as a genetic factor that might have increased the infection’s severity.
Impact on Hunter-Gatherer Communities
The findings add to growing evidence that suggests where plague might have originated, experts say — and also challenge ideas about what enabled plague to spread. The plague victims likely hunted, skinned, and butchered marmots for their meat and fur, which would have exposed members of the community to the bacteria.
Genetic research shed light on the kinship between children and adults buried in the cemeteries. Sometimes, siblings, parents, and children were buried together, suggesting the disease passed from one family member to another as they cared for one another — and a lack of understanding for how the disease spread.
Original reporting: El Paso News (HLL/CB) — read the source article.
