More than 200 million years ago, a cataclysm known as the Permian extinction destroyed nearly 97 percent of all living things. Its origins have long been a puzzle. Paleontologist Ward, fresh from helping prove that an asteroid had killed the dinosaurs, turned to the Permian problem, and he has come to a stunning conclusion: that the near-total devastation at the end of the Permian period was caused by rising levels of carbon dioxide leading to climate...

Presents an examination of the possibilty of life that is alien to planet Earth, providing a discussion of the nature of life itself, its limits, what alien life might be like, and how it can be created artificially.