One of very interesting places in the Second Life is an A-Life Experiment.
Besides being a place of exceptional beauty, it demonstrates something very interesting. Creators of the experiment are trying to build an artificial, self-regulating eco-system in the game. Participants are: sun, bees, birds, tress, flowers. All of them are scripted to do their part in the system. For example, bees are polluting flowers with "pollen" which contain "genes".