The author of this work is best known for her suggestion that mitochondria and chloroplasts, the energy-producing components of plant and animal cells, originally evolved as separate organisms and then merged with their host cells in a symbiotic union. She is also one of the founders, with James Lovelock, of the Gaia theory, the idea that the entire biosphere is a self-regulating meta-organism. This collection of essays explores the far-reaching implications of symbiosis as an evolutionary force, such as its role in brain development and the questions it poses for the existence of truly "individual" organisms.

Foreword by: P. Morrison