Symbiotic Planet: How Life Evolved Through Cooperation

From the origin of life to the classification and phylogeny of living organisms, from a discussion of Gaia--the belief that Earth operates like a living being--to a discussion of the underlying reasons for sex, iconoclastic biologist Margulis (coauthor, What Is Sex?, etc.) takes on many of the big questions in biology in this small, rambling and informal tract. In a book that is part autobiography and part biological primer, Margulis--the scientist most responsible for the theory that animal and plant cells originally arose by combining with simple bacteria--advances the idea that a large part of organic evolution can be explained by symbiosis, ""the living together in physical contact of organisms of different species."" Rather than convincing readers of this theory, however, she seems content to lavish most of her attention on basic biological concepts. While Margulis conveys a sense of the wondrous and intricate origins of life, many of the issues she touches upon here are more clearly and comprehensively dealt with in her other works. 11 b&w illustrations. (Nov.)