The Gaia hypothesis was first scientifically formulated in the 1960s by the independent research scientist Dr. James Lovelock, as a consequence of his work for NASA on methods of detecting life on Mars.[1][2] He initially published the Gaia Hypothesis in journal articles in the early 1970s[3][4] followed by a popularizing 1979 book Gaia: A new look at life on Earth.
The theory was initially, according to Lovelock, a way to explain the fact that combinations of chemicals including oxygen and methane persist in stable concentrations in the atmosphere of the Earth. Lovelock suggested using such combinations detected in other planets' atmospheres would be a relatively reliable and cheap way to detect life, which many biologists opposed at the time and since. Later other relationships such as the fact that sea creatures produce sulfur and iodine in approximately the quantities required by land creatures emerged and helped bolster the theory. Rather than invent many different theories to describe each such equilibrium, Lovelock dealt with them holistically, naming this self-regulating living system after the Greek goddess Gaia, using a suggestion from the novelist William Golding, who was living in the same village as Lovelock at the time (Bowerchalke, Wiltshire, UK). The Gaia Hypothesis has since been supported by a number of scientific experiments and provided a number of useful predictions, and hence is properly referred to as the Gaia Theory.
Since 1971, the noted microbiologist Dr. Lynn Margulis has been Lovelock's most important collaborator in developing Gaian concepts.
Until 1975 the hypothesis was almost totally ignored. An article in the New Scientist of February 15, 1975, and a popular book length version of the theory, published as The Quest for Gaia, began to attract scientific and critical attention to the hypothesis. The theory was then attacked by many mainstream biologists. Championed by certain environmentalists and climate scientists, it was vociferously rejected by many others, both within scientific circles and outside them.
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Daisyworld simulations
Run the Simulation and see result here - http://www.ph.ed.ac.uk/nania/daisyworld/daisyworld.html
Lovelock responded to criticisms by developing the mathematical model Daisyworld with Andrew Watson to demonstrate that feedback mechanisms could evolve from the actions or activities of self-interested organisms, rather than through classic group selection mechanisms.[18]
Daisyworld examines the energy budget of a planet populated by two different types of plants, black daisies and white daisies. The colour of the daisies influences the albedo of the planet such that black daisies absorb light and warm the planet, while white daisies reflect light and cool the planet. Competition between the daisies (based on temperature-effects on growth rates) leads to a balance of populations that tends to favour a planetary temperature close to that which is optimum for the daisy growth. Lovelock and Watson demonstrated the stability of Daisyworld by forcing the sun that it orbits to evolve along the main sequence, taking it from low to high solar constant. This perturbation of Daisyworld's receipt of solar radiation caused the balance of daisies to gradually shift from black to white but the planetary temperature was always regulated back to this optimum (except at the extreme ends of solar evolution). This situation is very different from the corresponding abiotic world, where temperature is unregulated and rises linearly with solar output. Later versions of Daisyworld introduced a range of grey daisies and populations of grazers and predators, and found that these further increased the stability of the homeostasis. More recently other research, modelling the real biochemical cycles of Earth, and using various "guilds" of life (eg. photosynthesisers, decomposers, herbivores and primary and secondary carnivores) has also been shown to produce Daisyworld-like regulation and stability, which helps to explain planetary biological diversity[citation needed].
This enables nutrient recycling within a regulatory framework derived by natural selection amongst species, where one being's harmful waste becomes low energy food for members of another guild. This research on the Redfield ratio of Nitrogen to Phosphorus shows that local biotic processes can regulate global systems (See Keith Downing & Peter Zvirinsky, The Stimulated Evolution of Biochemical Guilds: Reconciling Gaia Theory with Natural Selection).
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