In the last six years, researchers have untangled the origins of devastating human plagues, sequenced the genome of a Yersinia pestis strain responsible for the Black Death and explored how long this bacterium has been with humans. However, the information arising from this research begs more questions. How many variations of Y. pestis occurred during the 14–17th centuries, the second pandemic that began with the Black Death? Did these differences reflect the location in which the Y. pestis-positive skeletons were found? What were the geographic source or sources of these plagues? A recent PLOS ONE article examined Y. pestis found in German remains separated by 500km and 300 years to answer to some of these questions. Continue reading “The Black Death: World Traveler or Persistent Homebody?”