Scientists have found the oldest known evidence of the plague, which sparked deadly outbreaks 5,500 years ago – 200 years earlier than previously thought.
The disease has afflicted humans for thousands of years and wiped out a large part of the European population in the 14th century during what is known as the Black Death. Although rare, plague still exists today and is treated with antibiotics.
“To understand our own history, we believe that understanding the history of plague is very important,” said study co-author Eske Willerslev, an evolutionist at the University of Copenhagen in Denmark.
Willerslev and other researchers looked for traces of plague-causing bacteria in remains from four cemeteries near Siberia’s Lake Baikal. They found traces of plague DNA in the teeth of 18 former hunters.
Carbon dating of the bones showed that the plague caused two outbreaks, with the first cases discovered around 5,500 years ago.
The team found that the prehistoric plague developed in stages and infected several small families. It probably spread from marmots – large native rodents – when people ate their raw organs or touched infected skin during slaughter. The disease also traveled between people through coughing and sneezing, the authors said.
