The oldest strain of Yersinia pestis -- the bacteria behind the plague that caused the Black Death, which may have killed as much as half of Europe's population in the 1300s -- has been found in the remains of a 5,000-year-old hunter-gatherer. A genetic analysis publishing June 29 in the journal Cell Reports reveals that this ancient strain was likely less contagious and not as deadly as its medieval version.

 

‘What’s most astonishing is that we can push back the appearance of Y. pestis 2,000 years farther than previously published studies suggested,’ says senior author Ben Krause-Kyora, head of the aDNA Laboratory at the University of Kiel in Germany. ‘It seems that we are really close to the origin of the bacteria.’