The origin of the Black Death

was the Black Death, an outbreak of that ravaged Europe, the Middle East and north Africa between 1346 and 1353. Where it struck, it killed up to 60% of the population. Even after this first, exceptionally lethal wave had passed, local plagues continued for about 500 years, and the disease still spills over into people from rodent “reservoirs” from time to time. Insight into the Black Death’s origins came in 2012, when Cui Yujun’s team at the Beijing Institute of Microbiology and Epidemiology sequenced genomes of, the plague bacterium, collected from five countries. Dr Cui’s results suggested four lineages of the bug had emerged in quick succession during an evolutionary big bang. Calculations based on the estimated speed of evolution led them to suggest this so-called polytomy happened between 1142 and 1339.