The version of the bubonic plague kicking around today is indeed related to the one that wiped out a third of Europe’s population in the Middle Ages, researchers have confirmed, after DNA testing on 109 ancient skeletons buried in a mass victims' grave in London revealed a shared gene sequence. “At least this part of the genetic information has barely changed in the past 600 years,” one of the study’s authors tells the AFP.
“Without a doubt, the plague pathogen known today as (yersinia) pestis was also the cause of the plague,” he added. Of course, today’s version of the disease is drastically less deadly; an outbreak in India in 1904 killed just 3% of the population, and that was in the days before antibiotics. The scientists believe the medieval strain of the disease is likely extinct, but think they could eventually chart how it evolved. (Read more bubonic plague stories.)