One could e.g. run a sim of bounded intelligence agents competing with each other for resources, then pick the best one, that will implement the tit for tat and more complex solutions that work. It was already the case that for iterated prisoner's dilemma there wasn't some enormous number of amoral solutions, to the much surprise of AI researchers of the time who wasted their efforts trying to make some sort of nasty sneaky Machiavellian AI.

edit: anyhow i digress. The point is that when something is derivable via simple rules (even if impractical), like laws of physics, that should enormously boost the likehood that it is derivable in some more practical way.