Scientists may have found the oldest-ever evidence of the bubonic plague, locked away in an ancient flea trapped in amber.
In a study published this month in the Journal of Medical Entomology, researchers report that the 20-million-year-old flea found in what’s now the Dominican Republic — a new species dubbed Atopopsyllus cionus — contains structures thought to be an ancient strain of the bacteria that once devastated Europe and Asia.
The human plagues (bubonic, pneumonic and septicemic) are caused by the bacterium Yersinia pestis. Studies have found that Y. pestis developed its ability to kill humans quite recently — maybe not long before the first major outbreak about 1,500 years ago. It may have existed as a minor human infection for a few thousand years before that. It’s possible this flea contains an earlier version of Y. pestis that preyed upon other animal hosts.
