Evolutionary Catastrophes: The Science of Mass Extinction

Originally published in France in 1995, this slim volume by a professor of geology at the University of Paris attempts to explain the causes of mass extinctions that have occurred over the past 300 million years. Courtillot does a superb job of presenting evidence for and against the two most likely factors: collisions of large asteroids with the earth and extensive volcanic activity. Although the popular belief is that asteroids are responsible, Courtillot argues persuasively that all available data are more consistent with the volcanic theory. Indeed, seven of the world's mass extinctions occurred when volcanic activity was at its peak, while only one, the extinction that took place 65 million years ago and wiped out the dinosaurs, among many other species, appears to have coincided with the impact of a major asteroid. Courtillot also discusses the personalities of some of the leading figures on both sides of the debate, as well as the nature of science. The book is fairly technical, however, so its appeal to a general readership may be limited. Illustrations. (July)