The History of the Plague Gets a Rewrite

The plague's first victims weren't Neolithic farmers; it killed hunter-gatherers in Siberia 5,500 years ago, per a new study in Nature. Researchers have identified the oldest-known evidence of plague by testing teeth from prehistoric skeletons buried along the Angara River. DNA from Yersinia pestis was found in about 40% of them, though due to the challenges of working with ancient DNA, the researchers say they believe most of the analyzed skeletons were felled by plague. Several graves held multiple children—some siblings or cousins—who appear to have died at the same time, suggesting family-level outbreaks in small foraging communities.

The finding challenges the long-held view that plague emerged with the higher population densities that resulted during the Neolithic agricultural transition. (NBC News notes a single plague infection was previously detected in a hunter-gatherer who lived about 5,000 years ago in what is now Latvia, but that study found no sign of an outbreak.) Instead, researchers say it likely flared up periodically among hunter-gatherers living near certain wild animals, then spread within family groups. The AP reports the study suspects people were infected after eating the raw organs of large native rodents called marmots or during the course of butchering them.