Gaia hypothesis

The Gaia hypothesis (/ˈɡaɪ.ə/), also known as the Gaia theory, Gaia paradigm, or the Gaia principle, proposes that living organisms interact with their inorganic surroundings on Earth to form a synergistic and self-regulating complex system that helps to maintain and perpetuate the conditions for life on the planet.

The Gaia hypothesis was formulated by the chemist James Lovelock and co-developed by the microbiologist Lynn Margulis in the 1970s. Following the suggestion by his neighbour, novelist William Golding, Lovelock named the hypothesis after Gaia, the primordial deity who was sometimes personified as the Earth in Greek mythology. In 2006, the Geological Society of London awarded Lovelock the Wollaston Medal in part for his work on the Gaia hypothesis.

Topics related to the Gaia hypothesis include how the biosphere and the evolution of organisms affect the stability of global temperature, salinity of seawater, atmospheric oxygen levels, the maintenance of the hydrosphere, and other environmental variables that affect the habitability of Earth.

The Gaia hypothesis was initially criticized for being teleological - implying the Earth purposefully maintains an atmosphere suitable for life - but this interpretation was rejected by Lovelock. The Gaia hypothesis continues to attract criticism, and today many scientists consider it to be only weakly supported by, or at odds with, the available evidence.

The Gaia hypothesis argues that organisms co-evolve with their environment. That is, organisms influence the abiotic, not just the biological environment, and in co-development the abiotic environment influences biota via some sort of a Darwinian process, which may indicate an evolution of a collaborative reciprocal evolving life habitat. In 1995, Lovelock gave evidence of this biotic-abiotic relationship in his second iteration of his conjecture within the book Ages of Gaia. This theory states the evolution from the world of the early warm-loving bacteria and methanogenic bacteria towards the oxygen-enriched extant atmosphere, that is, today's atmosphere, which we know is the Holocene and this is a supportive environment of more complex life than primordial times. As each individual species or other systems pursue their self-interest, their combined actions may have counterbalancing effects on the abiotic and biotic environment. Opponents^[who?] of this view sometimes reference examples of events that resulted in dramatic change rather than stable equilibrium, such as the conversion of the Earth's atmosphere from a reducing environment to an oxygen-rich one at the end of the Archaean and the beginning of the Proterozoic periods.^{[citation needed]}

Less accepted versions of the Gaia hypothesis claim that changes in the biosphere are brought about through the coordination of living organisms and maintain those conditions through homeostasis. In some versions of Gaia Hypothosis, 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.

Among the precursors of the Gaia hypothesis are Russian scientists such as Piotr Alekseevich Kropotkin (1842–1921), Rafail Vasil’evich Rizpolozhensky (1862 – c. 1922), Vladimir Ivanovich Vernadsky (1863–1945), and Vladimir Alexandrovich Kostitzin (1886–1963).

The Gaia paradigm was an influence on the deep ecology movement.