Extinction Is Normal—Mass Extinction Is Not
Species regularly appear through speciation and disappear through extinction. In fact, nearly all plant and animal species that have ever lived on Earth are now extinct.Extinction and Survival
Sometimes the Losses Spike
Mass extinction events slash diversity far faster than the usual background rate. The Permian–Triassic event was even more severe than the one that ended the non-avian dinosaurs, with about 96% of marine species lost.Extinction and Survival
