The concept of Gaia resonates with a wide range of people -- from nature lovers, theologians, and philosophers to environmental and earth systems scientists. The term, which scientist James Lovelock, originator of the Gaia hyposthesis, borrowed from Greek mythology, refers to the interacting system of life, soil, atmosphere, and ocean. Like the interiors of organisms, Gaia contains complex cycles and material transformations driven by biological energy. Gaia's inclusion of life means that from some perspectives it resembles life. But Gaia also differs from organisms in significant ways. Although it has changed through time, it does not evolve in a Darwinian sense. Whereas organisms are open, flow-through systems, Gaia is relatively closed to material transfer across its borders. It exists according to its own level of operating rules, a level as complex as that of organisms and the subject of the emerging field known as Earth physiology, or geophysiology.Blending science and evocative imagery, Gaia's Body offers an engaging introduction to this new field. It explains how every important chemical in the atmosphere is regulated by living processes -- why, for example, strange, spaghetti-like bacteria off the coast of Chile have an intimate connection with the plants in Long Island backyards; why "biochemical guilds" may be Earth's most important unit of life; and how scientists have detected the biosphere's "breathing." The book includes a Preface written for the paperback edition.