Extinction

Some 250 million years ago, the earth suffered the greatest biological crisis in its history. Around 95 percent of all living species died out¿a global catastrophe far greater than the dinosaurs'' demise 185 million years later. How this happened remains a mystery. But there are many competing theories. Some blame huge volcanic eruptions that covered an area as large as the continental United States; others argue for sudden changes in ocean levels and chemistry, including burps of methane gas; and still others cite the impact of an extraterrestrial object, similar to what caused the dinosaurs'' extinction.

Extinction is a paleontological mystery story. Here, the world''s foremost authority on the subject provides a fascinating overview of the evidence for and against a whole host of hypotheses concerning this cataclysmic event that unfolded at the end of the Permian.

After setting the scene, Erwin introduces the suite of possible perpetrators and the types of ev