The Sixth Extinction

Five mass extinctions, etched in the fossil record, attest to life's precarious, unpredictable course. One such catastrophe, occurring 65 million years ago, wiped out the dinosaurs and ushered in the age of mammals. In another global disaster, 225 million years ago, more than 95% of marine animal species vanished. A sixth mass extinction is inevitable, according to eminent paleoanthropologist/conservationist Leakey and ecologist/evolutionary biologist Lewin, who collaborated on Origins and Origins Reconsidered. Human beings, by destroying tropical rain forests and driving tens of thousands of species into extinction, are dangerously reducing biodiversity, damaging ecosystems and possibly precipitating the next major mass extinction, which could number Homo sapiens among its victims, the authors warn. This eloquent and important study maintains that mass extinctions were major creative factors in shaping evolution, opening ecological niches to survivors--only we may not be so lucky next time around. Illustrated. (Oct.)