The evolution of climate on Daisyworld
The dashed curve shows the rise of temperature on the model planet due to increasing stellar luminosity, with no life present, and the solid line shows how a constant temperature is maintained with life (in the form of dark and light dasies) first warming, and then cooling, the surface

Daisy World: a model for Gaia

Welcome to planet Daisyworld: a computer model planet like the Earth, orbiting a star like the Sun, but on which the only species are light and dark daisies. In the distant past, when the star was less luminous, only the equatorial region would have been warm enough to permit the growth of daisies, and the dark daisies would have flourished, because they absorb more warmth from sunlight. Gradually the dark daisies would have colonized most of the planet, and by absorbing heat begun to warm the surface environment.
However, as the star’s luminosity increased the lighter daisies would have been favoured instead, due to their natural ability to keep themselves and the planet cool, by reflecting more light. Finally, when the heat flux from the star becomes so great that not even the white daisies can keep the planet cool enough for life, deserts spread from the equator and finally the system fails and Daisyworld dies. (see variation 30)