Six years ago, a new infection began popping up in four different hospitals on three different continents, all around the same time. It wasn’t a bacteria, or a virus. It was ... a killer fungus. No one knew where it came from, or why. Today, the story of an ancient showdown between fungus and mammals that started when dinosaurs disappeared from the earth. Back then, the battle swung in our favor (spoiler alert!) and we’ve been hanging onto that win ever since. But one scientist suggests that the rise of this new infectious fungus indicates our edge is slipping, degree by increasing degree. This episode was reported by Molly Webster, and produced by Molly and Bethel Habte, with production help from Tad Davis. Special thanks to Julie Parsonnet and Aviv Bergman.  Support Radiolab today at Radiolab.org/donate.   Further Fungus Reading: NYTimes feature on the mysterious rise of Candida auris.   Arturo's paper: “On the emergence of Candida auris, Climate Change, Azoles, Swamps, and Birds”, by Arturo Casadevall, et al. “On the Origins of a Species: What Might Explain the Rise of Candida auris?”, a report from the CDC.