http://megaswf.com/simple_serve/102223/

Basically the bike keeps evolving using traits of previous generations until it becomes more suitable to pass over the terrain. Pretty neat if you haven't seen it before.

what effect does mutation rate have on the reults?

Well, with a lower mutation rate, it will take longer to maintain a stable "species" of car capable of traversing far on the track.

With a very high mutation rate, you may never establish a stable strain of car capable of moving along the track, because a possible good mutation still has a high chance of being further mutated (I'm assuming) to become unfavorable.

hey thats pretty neat!