I surveyed several leading high school environmental science and biology texts for discussions of mass extinctions. Most of them do clarify that extinction is part of evolution and that really massive extinctions open ecosystem niches that may be occupied by new species. A couple of the books explain that the final nice mass extinction, the one that wiped out the dinosaurs 65 million years ago, was followed by the fast emergence of mammals. (One may make a superb argument that people have the fifth mega-extinction to thank for his or her present dominant role on the planet.) The environmental science texts talk about the current lack of biodiversity. One of the books that I looked at actually included the idea that we could possibly be in a sixth major mass extinction. In all cases the discussion covered just some pages in a textual content that is 600 to over 1,000 … Read more