http://rednuht.org/genetic_walkers/
Using simple evolutionary systems in games can often be a way to develop worthwhile opponents in a reasonably short period of time.  When I was working with Blue Planet Software while they were in production an RTS called “Hanesakegassen” they began to set up “AI’s” to play against one another, over and over.  Each new version of the bot got to keep what the previous bot had recorded with regards to tactics.  What worked, what didn’t.  They (the bots) didn’t really ever know the *why* they just knew that the blue opponent always spent an extra minute collecting ammo, or that the green opponent hated to fortify areas with water.
The HTML tool above is a simple (by which i mean clean and straightforward, the code behind it is probably more complex than I can parse) example of this. Â A bipedial, jointed figures is trying to “learn” to walk. Â The most successful ones are copied and try again. Â And again. Â And again.