How the Plague Hijacked Fleas to Kill the World

This article was originally posted on RealClearScience.

The bacterium that causes bubonic plague or Black Death, Yersinia pestis, is a relatively new species. Research suggests it diverged from its nearest living bacterial ancestor no more than 6,400 years ago. During this transition, the genetics of Y. pestis changed. Most notably, it acquired genes that helped it survive inside fleas. Continue reading