The Gaia hypothesis, also known as Gaia theory or Gaia principle, proposes that organisms interact with their inorganic surroundings on Earth to form a self-regulating, complex system that contributes to maintaining the conditions for life on the planet.
The hypothesis was formulated by the scientist James Lovelock and co-developed by the microbiologist Lynn Margulis in the 1970s.
Fringe science versions of the hypothesis claim that changes in the biosphere are brought about through the coordination of living organisms and maintain those conditions through homeostasis.
In Gaia philosophy, all lifeforms are considered part of one single living planetary being called Gaia. In this view, the atmosphere, the seas and the terrestrial crust would be results of interventions carried out by Gaia through the coevolving diversity of living organisms. However, the Earth as a unit does not match the generally accepted biological criteria for life itself, for example, there is no evidence to suggest that "Gaia" has reproduced. This argument is countered by the fact that mules do not reproduce, yet they are also classified as living.
The Gaia theory posits that the Earth is a self-regulating complex system involving the biosphere, the atmosphere, the hydrospheres and the pedosphere, tightly coupled as an evolving system. The theory sustains that this system as a whole, called Gaia, seeks a physical and chemical environment optimal for contemporary life
Gaia hypothesis - Wikipedia, the free encyclopedia