Sim Earth

Sim Earth is a simulation computer game in which the player can control the ecosphere[?] and development of an entire planet, including varying its atmosphere, temperature, landmass etc. The player can place various forms of life on the planet and watch it evolve[?] and possibly become civilized. The eventual aim of the game is for your planet to evolve intelligent life and an advanced civilisation, but this is very difficult to achieve.

The game models the Gaia hypothesis, and one of the options available to the player is the simplified "daisy world" model. The daisies change color depending on the temperature (dark for cold and bright for hot). This is because the black daisies are more tolerant of low temperatures, but they decrease the planet's albedo and cause the planet to warm. Then they die off and are replaced by the white daisies, more tolerant of warm temperatures; inversely, these increase the planet's albedo and cause it to cool. These reactions are meant to demonstrate that the biosphere of the planet reacts as a whole to preserve itself.