HAT IS GAIA?
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Gaia is a theory about the evolution of the Earth. A theory that sees
the evolution of the species of organisms by natural selection and the
evolution of the rocks, air and oceans as a single tightly coupled
process. In Gaia the organisms and their material environment together
constitute a system which is able to self-regulate climate and
atmospheric composition.
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SimEarth is based on the Gaia theory, as proposed by James Lovelock. Gaia
theory is controversial, and not an accepted truth in all
scientific circles.
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GAIA
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The Gaia hypothesis comes in two versions: the weak Gaia and the
strong Gaia. The strong Gaia says that the Earth is alive. The
weak Gaia says that life may have some regulatory effect on some of
the dynamic systems of the planet. We will explore in this manual
only the strong Gaia version. Please understand that although this
hypothesis is controversial and therefore not generally accepted in
the scientific community, it provides a useful framework for
understanding the Earth.
Gaia was developed by Lovelock during the time NASA was preparing
the Viking explorer for a trip to Mars. He was designing
instrumentation to test if there was life there. But in order to
test for life, Lovelock had to ask the question, "What is life?"
This work provided Lovelock the opportunity to reevaluate this
fundamental question.