The canary's death in a coalpit alerted miners to odourless, poisonous gases but does the decrease in songbirds in the northern hemisphere foreshadow an ecological collapse? In this book paleontologist Niles Eldredge unveils his theory of extinction by exploring the evidence from the first living forms 3.5 billion years ago to the present. The book illuminates the most pressing environmental questions of today such as what causes extinction and are human beings accelerating extinction in other species?