Here's a neat site.
It shows the genetic algorithm in action as it evolves a car 'designed' to go faster and further over a terrain of peaks and troughs designed to filter out the weakest, most unstable and least efficient.
You don't need to do anything other than watch, but you can play around with a few settings like the maximum number of wheels - try 4 or 5 - or the mutation rate.
The first generation is just random stuff, often going nowhere with maybe a few making some progress. The trick is, just like in life, that the best are favoured and hybridize so the best wheel size, axle torque, body shape etc are more likely to be in the next generation. Plus a few more random variations thrown in.
Pretty soon a few different models will evolve. They might even hybridize and produce a new supercar; or they may be incompatible and fail, just like in real life.
Anyway, especially if you don't believe in evolution, take a look. Leave it running overnight and wake up to some pretty nifty cars zipping across the landscape. Remember, everything apart from the selection process is random. The only thing that makes it non-random is selection favouring the most successful models, just like in real life.
Careful though; it can be addictive.