In the geological record, there are five major mass extinctions the "Big Five." The most famous happened at the end of the Cretaceous Period, when the dinosaurs and two-thirds of all marine animal species were wiped out, opening the door for the age of mammals and the rise of Homo Sapiens. Using this example as a springboard, David M. Raup leaps into an egaging discussion of the theories, assumptions, and difficulties associated with the science...