GAIA HYPOTHESIS  Created by James Lovelock in 1969 (but not published until 1979)  Named after the Greek Goddess Gaia who was the Earth Goddess

 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.  Properly defined as "hospitality" as a full homeostasis (ability to self regulate the internal environment)

4 factors that work together  Biosphere  Oceans  Atmosphere  Soil

3 Ways Earth regulates itself 1. Surface Temperature – has remained constant despite the energy increase by the Sun 2. Atmospheric Composition – remains constant even though it should be unstable 3. Ocean Salinity – remains constant despite the fact that river salts should have raised the ocean salinity much higher

Daisyworld  Lovelock used this computer simulation to demonstrate the hypothesis  Hypothetical world orbiting a sun whose temperature is slowly increasing in the simulation  Planet has two different species of daisy as its only life form: black daisies and white daisies  h/gaia1.htm h/gaia1.htm h/gaia1.htm