Cover for Drabblecast episode 278, The End of the World as We Know It, by Adam S. DoyleBetween 1347 and 1450 AD, bubonic plague overran Europe, killing some 75 million people. The plague, dubbed the Black Death because of the black pustules that erupted on the skin of the afflicted, was caused by a bacterium now known as Yersinia pestis. The Europeans of the day, lacking access to microscopes or knowledge of disease vectors, attributed their misfortune to an angry God. Flagellants roamed the land, hoping to appease His wrath. “They died by the hundreds, both day and night,” Agnolo di Tura tells us. “I buried my five children with my own hands . . . so many died that all believed it was the end of the world.”

Today, the population of Europe is about 729 million…