(R)evolutionary simulations

I'm currently looking at a program called "Darwin Pond". Some of you may have heard of it. If you haven't, look it up in google. It simulates a simple ecosystem that consists of food (that you can tweak to replicate quickly, slowly, spread quickly or slowly, how much energy it gives etc.) and swimmers. Swimmers are the evolutionary things in this program. They mutate, breed, and eat stuff. I think it is a great demonstration of how evolution works. The selective pressures are thus:

How quickly a swimmer can get food (coupled with how much energy it takes... e.g. A fast, but inefficient way of getting food may result in extinction after a few generations, or always eating and never breeding)
How attractive a swimmer is to another (goes against efficiency... More legs = more attractive, but less efficient)
Efficiency
Amount of food

I am currently running this program, and have gotten up to my second "mass extinction". Previously, the dominant species was a three legged purple thing, that has apparently bred itself out. It can still be seen as a few hybrids (green/blue/purple three leggers). By the end of its run, it was fairly fast, but also rather inefficient. The eventual destruction of the species was a result of being too concentrated, and consuming all of the food in its area. While it did so, another area had an increase in food (due to a lack of swimmers). The closest swimmers to this new source were green, single legged swimmers.

The green swimmers are currently heading in the same direction of the purple swimmers, although they are much more spread out. I am fairly tempted to leave the program over night, but I don't want to miss whatever species that may exist in between (the game has no fossils). A large number of hybrids have also died out recently. If you guys want, I'll keep you posted.

I think Tenspace posted an evolution simulator earlier. It was very difficult to achieve stable populations of both predator and prey unless you allowed both predator and prey to mutate, which implies (to me), that evolution is not only a feature of, but necessary for life.

Anyway, are you able to let the "food" also mutate? You would probably avoid those mass extinctions if you could.

Argh. The food doesn't mutate. The food is simply a selective pressure, fairly constant. I left the program running over night, and the green critters have disappeared. When I went to bed, they were being replaced by blue swimmers. Those too have been replaced by blue/purple swimmers.

I've also since changed the food from a fairly close spread to a far spread, which changes it from fast growth and rapid extinction, to where growth and death are fairly constant, with the number of swimmers fluctuating between 190 and 210, and the food between 8 and 60.

[DrunkMonkey]

http://www.ventrella.com/GenePool/gene_pool.html

This one is the same, but better. Much better graphics and randomness- you can even edit their sexual preferences.

Still no prey though- that would have made this one the best.

[DrunkMonkey]

The genepool one is awesome. I started out with all green "froggies" and now I have all kinds of strange creatures- there are some red ones that don't move, don't eat, and only reproduce when another animal looking to mate stops by.