SimEarth - The Living Planet

The game depicts what you roughly get when people go into marasmus. Maxis has twisted their Sims into this game. You control different species of life, aquatic and terrestrial, in major eras (geological, evolutionary, civilization, technological). Some sort of energy is given as a resource (what is meant by it is unclear). Life forms for each time period are different, so you need to know clearly what to do and how to do it. And most importantly, why. Single-player game.