Evolution

[Abishalom]

Actually, we can test it and we have. It's called computer simulations. Input a genome, methods of genome replication and mutation, and code for how natural selection works. The output is evolution. Here is a very simple simulation I came across.

http://www.youtube.com/watch?v=GuWJ1ZiwO2g

I'm talking about in real life...you know with real organisms. It's never been observed but always presumed to be true (despite absolutely no evidence). BTW computer simulations require a designer (so I doubt you want to use this as "evidence" for evolution).