Excellent evolution simulation
For anyone who hasn't seen this before, may I submit to you Gene Pool, a simulation of darwinian evolution and both natural and sexual selection in its purest form.
I have used this program many times to further the cause of evolution education to doubting theists and eager students. Basically, it has a bunch of biomorph-like creatures that go through embryonic development with a set of simple genes that determine how it grows, how it moves and what mate it finds "attractive". Each creature has both a mouth and a sexual organ, and has two goals in life: Eat and Mate. The varied creatures (called swimbots) compete for pellets of food and mates. Once they mate, they create a child with genes similar to both parents, with minor mutations. Over time the better swimmers, the more efficient turners and the most "attractive" swimbots survive and reproduce. The ecosystem settles into a stable cycle and natural selection ensures that there will be a few dominant competing species. It may take a few hours, but eventually the screen should be filled with higly efficient swimming and eating machines created by nothing more than a few simple rules and natural selection.
Please forgive me if this has already been posted before.