Scientists say in a new study in the journal Nature that they've found DNA from the bacterium that causes plague in prehistoric graves in Siberia, changing long-standing thoughts on the disease. File photo by Tamas Soki/EPA
June 17 (UPI) -- Scientists have found the oldest known signs of a plague outbreak in DNA evidence from hunter-gatherer graves in Siberia, a study published Wednesday in the journal Nature said.
The researchers said the study involves early plague strains from outbreaks starting about 5,500 years ago among hunter-gatherers living near Lake Baikal in southeast Siberia. The graves studied contained skeletons from multiple generations, the study said.
Testing on the skeletons' teeth showed DNA from the bacterium that causes plague -- Yersinia pestis -- in nearly 40%.
"These findings show that plague outbreaks happened earlierthan previously thought and were indeed lethal," the study said. "We contend that the occurrence of outbreaks ... challenges the notion that higher population densities and lifestyle changes during the Neolithic agricultural transition were prerequisites for plaque epidemics."
