To quote a famous fictional lion, the Earth is a beautiful circle of life — predators and prey, plants and animals keeping each other in perfect balance. This idea — of Earth's lifeforms as epitomizing a collective, life-cultivating system — has a long history: the ancient Greeks called Earth "Gaia," the mother of all life. In the 1970s, two scientists hypothesized that planet Earth is really one giant super-organism, with all animals, plants, fungi and other life actively influencing (and encouraging) one another's evolution; Lynn Margulis, an evolutionary biologist, and James Lovelock, a scientist, environmentalist and futurist, accordingly called their theory the Gaia hypothesis.
"Life clearly does more than adapt to the Earth," Lovelock told Salon in an interview from 2000. "It changes the Earth to its own purposes. Evolution is a tightly coupled dance, with life and the material environment as partners. From the dance emerges the entity Gaia."
