Should we be horrified by extinction? Charles Darwin didn’t think so. In On the Origin of Species, he mocked the catastrophist view of extinction as scientific illiteracy: “So profound is our ignorance, and so high our presumption, that we marvel when we hear of the extinction of an organic being; and as we do not see the cause, we invoke cataclysms to desolate the world!” Extinction was no cataclysm. Without it, the human species—along with all other life—would never have evolved.