This notion that in order to have learning AI you need programs that modify their own code is preposterous, but also very common. The divide between code and parameters is an arbitrary one, and it's much more productive to think of learning as changing parameters.
The other thing that should be mentioned is that adaptive AI is something you probably don't want in a video game. It's hard enough to debug a non-adaptive AI to make sure that the bad guys don't get stuck in corners or do other stupid things that break the illusion. If the AI can change once it's in the hands of the player, this can become a much harder problem, unless the adaptability is very limited and controlled.
Could you point me in the direction of a good starting place to learn the basics of AI. I don't intend to dive into it much as I stated I am mainly graphics oriented however I would like to have a better understanding of what I am talking about so that in the future I don't make myself look foolish like I did in this post.
I'd check out the first post on the AI Forum...it'll point you to many great books and sites to get your AI blood flowing!