Radiocarbon dating of plague genomes was off by up to 150 years. A new method fixes that.

A refined phylochronology of the second plague pandemic in Western Eurasia

Ancient DNA has recovered over 100 Yersinia pestis genomes from the Second Plague Pandemic, but most lack precise dates—radiocarbon intervals often span more than a century, making it impossible to link them to documented outbreaks. Researchers present 11 new genomes from Estonia, the Netherlands, Russia, Switzerland, and England (1349–1710) and introduce Phylogenetically Informed Radiocarbon Modeling (PhIRM), which combines phylogenetic order with radiocarbon dates. The refined dates let them tentatively associate all 75 analyzed genomes with historical plague outbreaks.