‡  Morjorie L. Reaka-Kudia, et al., Biodiversity II, Understanding and Protecting our Biological Resources, Washington: National Academies Press, 1997. “Biologists have come to recognize just how little we know about the organisms with which we share the planet Earth. In particular, attempts to determine how many species there are in total have been surprisingly fruitless.” Myers: “We have no way of knowing the actual extinction rate in the tropical forests, let alone an approximate guess.” In Lomborg, p. 254.