Scientists find oldest evidence of plague outbreak dating back 5,500 years

Researchers have identified the oldest-known evidence of the plague, revealing that deadly outbreaks of the disease struck human populations as far back as 5,500 years ago—approximately 200 years earlier than previously believed.

The discovery sheds light on the ancient history of a disease that has plagued humanity for millennia, including its devastating impact during the 14th-century Black Death, which wiped out a significant portion of Europe’s population. While rare today, the plague still exists and can be treated with antibiotics. “To understand our own history, we believe that understanding the history of plague is extremely important,” said Eske Willerslev, an evolutionary geneticist at the University of Copenhagen and co-author of the study.

The research team, led by Willerslev, examined ancient DNA from the remains of 18 hunter-gatherers buried in four cemeteries near Siberia’s Lake Baikal. By analyzing plague-causing bacterial DNA found in the individuals’ teeth and dating the carbon in their bones, scientists determined that the disease was responsible for two prehistoric outbreaks, with the earliest cases occurring around 5,500 years ago.

The study also revealed that the prehistoric plague evolved in stages and primarily affected small family groups. The disease likely originated from marmots, large rodents native to the region. Researchers believe it spread to humans when they consumed raw marmot organs or handled infected animal hides during butchery. Additionally, the plague could have been transmitted between people through coughing and sneezing.

This groundbreaking discovery provides crucial insights into the ancient origins of one of humanity’s deadliest diseases and highlights the importance of understanding its history to better comprehend its impact on human populations.