You may want to look into symbolic regression. I often find that by applying a downward pressure on the fitness of less parsimonious individuals as well as one

You may want to look into symbolic regression. I often find that by applying a downward pressure on the fitness of less parsimonious individuals as well as one or more substitution operators (where applicable) you can get very elegant results. Add constraints or other fitness bonuses for specific types of relationships you are looking for and you might be surprised by what cool things you can find. Also a great excuse to learn Common Lisp if you haven't already. A good starting point is John Koza's first book on Genetic Programming.