Why are there so many kinds of organisms, and why do they cluster into discrete groups associated with particular locales? These and other ecological questions find answers in the expansive version of evolution that is presently emerging. Heredity, variation, natural selection, and adaptation are rooted in the level of genes, but incorporate features that grow out of the many tiers of biological organization. The communitarian view of life complements the one focused on the individual organism, and requires us to reexamine the meaning of both organism and individual. It embraces broad-gauge phenomena such as nutrient cycles, and gave birth to Gaia: the vision of Earth as a self-regulating system that has kept our planet hospitable to life for nearly 4 billion years.
The Tangled Bank, Ecology, and Gordian Knots