Researchers at Germany's University of Tübingen and elsewhere have reconstructed the genome of the pathogen that cause the Black Death, the plague that killed about 50 million people in Europe between 1347 and 1351, Technology Review's Emily Singer reports.
As this Nature video shows, the researchers sequenced DNA derived from the bones and teeth of four plague victims who had been buried in London:
The Tübingen-led team, whose work was published online in advance in Nature this week, took fragments of Yersinia pestis DNA from the victims' remains, and managed to separate that ancient genetic material from recent contamination by other organisms. They then sequenced the ancient DNA and compared the results to modern Y. pestis strains, and found that the ancient plague bug is almost identical genetically to modern Y. pestis, Tech Review's Singer adds. "Researchers say it's not yet clear why this ancient version was so deadly or why the modern versions, which are genetically highly similar, are less virulent," Singer says. "The devastation of the Black Death may have been due to the climate at the time … and the onset of a new bacterium in an immune-challenged population."