Black Death DNA Mapped Out

One of the deadliest bacteria of all time is the first ancient pathogen to have its entire genetic code deciphered.

Canadian and German researchers have mapped out the genetic code of the bacteria responsible for the black plague, which killed between 75 and 100 million Europeans in the 1300s. The bacteria, known as Black Death, is the first pathogen that scientists have been able to completely unravel, giving them insights into how the bacteria evolved over time. Researchers from McMaster University and the University of Tuebingen studied the skeletons of English plague victims from the 1300s. They found that the bacteria, whose scientific name is Yersinia pestis, hasn't changed too much in the nearly 700 years since it ravaged Europe. While the bacteria can still cause bubonic plague, the researchers believe its virulency in Medieval Europe was due more to the low sanitary standards of the time (they did throw buckets of human waste into streets, after all) than the bacteria itself. As sanitation improved and humans developed better resistance to the bacteria, the bacteria's impact on humanity waned. The researchers hope that they can glean further insights into epidemiology by monitoring further changes to the bacteria's DNA as time progresses.