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Gaia Hypothesis. Created by James Lovelock in 1969 (but not published until 1979) "the biosphere - atmosphere, oceans, climate, Earth's crust and biota, living organisms, is regulated as a homeostatic system in conditions comfortable for the living organisms".
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Created by James Lovelock in 1969 (but not published until 1979) • "the biosphere - atmosphere, oceans, climate, Earth's crust and biota, living organisms, is regulated as a homeostatic system in conditions comfortable for the living organisms"
Hypothesis: that the entire mass of living matter on Earth (the biosphere) functions as a single and vast superorganism that actively modifies its planet to produce the environment that suits its needs.
What is the Gaia Hypothesis? • Life itself is responsible for maintaining the stability of Earth’s climate. • The Earth has remained habitable because in some sense it is “alive” • Biota manipulate their environment to optimize conditions for life.
Gaia theory (or hypothesis), it was implied that the conditions such as climate of the Earth were regulated (around life-favourable values) 'by and for the biota'. It is the system as a whole, organisms and environment, that forms a closely-coupled self-regulating system Causes for the regulation are at the level of the whole system rather than individual isolated parts.
3 Ways Earth regulates itself • Surface Temperature – has remained constant despite the energy increase by the Sun • Atmospheric Composition – remains constant even though it should be unstable • Ocean Salinity – remains constant despite the fact that river salts should have raised the ocean salinity much higher
GAIAN ATTRIBUTES • Earth is a super-organism • Biota and physical environment are so tightly coupled they are considered a single organism. • The climate and chemical composition of Earth are kept in homeostatis at an optimum by and for the biosphere. • Recognizes emergent properties. (Such as Salinity, Air Temperature)
The nature of science • Science is a systematic way of understanding nature. • Scientific knowledge changes. • Science does not produce “truths”. However, science produces theories. Is this clear? A theory is broad in scope. It helps us make predictions about other phenomena. It is supported by a large body of evidence.