Gaia theory predecessors

Long before Lovelock proposed his Gaia hypothesis, there had been a number of religious, mythological, and philosophical ideas which had a Gaia-like conceptual basis.

• Many religious mythologies had a view of Earth as being a whole that is greater than the sum of its parts. (e.g. some Native American Indian religions.
• Lewis Thomas[?] held that Earth should be viewed as a single cell; he derived this view from Johannes Kepler's view of Earth as a single round organism.
• Teilhard de Chardin, a paleontologist and geologist, believes that evolution unfolded from cell to organism to planet to solar system and ultimately the whole-universe as we humans see it from our limited perspective. de Chardin he later influenced Thomas Berry[?] and many Catholic humanist[?] thinkers of the 20th century.

None of these ideas are considered scientific hypotheses; by definition a scientific hypothesis must make testable predictions. As the above claims are not testable, they are outsides the bounds of science. These are conjectures and perhaps can only be considered as social and maybe political philosophy; they may have implications for theology.

Gaia in biology and science

Buckminster Fuller is generally credited with making the idea respectable in Western scientific circles in the 20th century. Building to some degree on his observations and artifacts, e.g. the Dymaxion Map of the Earth[?] he created, others began to ask if there was a way to make Gaia theory scientifically sound.

The first such attemp was the Gaia Hypothesis by James Lovelock, a U.K. chemist. While controversial at first, various forms of this idea became accepted to some degree by many within the scientific community. A variant of this hypothesis was developed by Lynn Margulis, a microbiologist, in 1979. Her version is sometimes called the "Gaia Theory" (note uppercase-T). Her model is more limited in scope than the one that Lovelock proposed.

Gaia theory remains a spectrum of hypotheses, from undeniable to radical. At one end is the undeniable statement that the organisms on the Earth have radically altered its composition. In this view, the Earth's biosphere effectively acts as if it is a self-organizing system which works in such a way as to keep its systems in some kind of equilibrium that is conducive to life. Biologists usually view this activity as an undirected emergent property of the ecosystem; as each individual species pursues its own self-interest, their combined actions tend to have counterbalancing effects on environmental change. Proponents of this view sometimes point to examples of life's actions in the past that have 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.

A very small number of scientists, and a much larger number of environmental activists, claim that Earth's biosphere is consciously manipulating the climate in order to make conditions more conducive to life. Scientists contend that there is no evidence to support this belief, which has only come about because most people do not understand the concept of homeostasis. Many non-scientists instinctively see homeostasis as an activity that requires conscious control, although this is not so. This leads to some confusion on both sides, and the labels mysticism and scientism are applied to some adherents of the theory.

An overview of the scientific view of Gaia theories is found in Gaia theory in biology.

Gaia in the social sciences

A social science view of Gaia theory is the role of humans as a keystone species.
If they act to prevent climate change, primate extinction, etc., then they might make a homeostasis with their own cognition.

Gaia in politics

Some radical political environmentalists who accept some form of the Gaia theory call themselves Gaians. They actively seek to restore the Earth's homeostasis - whenever they see it out of balance, e.g. to prevent manmade climate change, primate extinction, or rainforest loss[?].
In effect, they seek to cooperate to 'become' the "system consciously manipulating to make conditions more conducive to life".
Such activity 'defines' the homeostasis, but for leverage it relies on deep investigation of the homeorhetic balances, if only to find places to intervene in a system which is changing in undesirable ways.

Gaians are attempting to create a new ideology which fuses conclusions from science and politics; they see this as a a protoscience of human ecology. These ideas include the idea of humans as the keystone species, say act to prevent climate change, primate extinction, etc., and might deliberatly make a homeostasis with their own cognition. deliberately maintaining the balances of the entire biosphere.
One is not passively asking "what is going on", but rather, "what to do next", e.g. in terraforming or climate engineering or even on a small scale as gardening. Changes could thus be planned, consented to by many people, and very deliberate, as in urban ecology[?] and especially industrial ecology. See arcology for more on this 'active' view.
Gaians argue that it is a human duty to act as such - committing themselves in particular to the Precautionary Principle.

Such views began to influence the Green Parties, Greenpeace, and a few more radical wings of the environmental movement. These views dominate some such groups, e.g. the Bioneers[?]. Some refer to this political activity as a separate and radical branch of the ecology movement, one that takes the axioms of the science of ecology in general, and Gaia theory in particular, and raises them to a kind of theory of personal conduct or moral code.

Semantic debate

The question of "what is an organism" and at what scale is it rational to speak about organisms vs. biospheres, give rise to a semantic debate.
We are all ecologies in the sense that our (human) bodies contain gut bacteria[?], parasite species, etc., and to them our body is not organism but rather mre of a microclimate or biome. Applying that thinking to whole planets:

The argument is that these symbiotic organisms, being unable to survive apart from each other and their climate and local conditions, form an organism in their own right, under a wider conception of the term organism than is conventionally used. It is a matter for often heated debate whether this is a valid usage of the term, but ultimately it appears to be a semantic dispute. In this sense of the word organism, it is argued under the theory that the entire biomass of the Earth is a single organism (as Johannes Kepler thought).

Unfortunately, many supporters of the various Gaia theories do not state exactly where they sit on this spectrum; this makes discussion and criticism difficult.

More speculative versions of Gaia, including all versions in which it is held that the Earth is actually conscious, are currently held to be outside the bounds of science. The views of self-proclaimed political Gaians are in this category.

External links

• Gaia: Argument over a single word (http://www.colorado.edu/iec/FALL299RW/eco)
• The Gaia Hypothesis (http://www.oceansonline.com/gaiaho.htm)
• Gaia: Science, Metaphor, or Myth? (http://www.lawrence.edu/dept/environmental_studies/gaia)