Sort:  

It's an explanation of how monkeys and humans could both have evolved. Everything about the world hasn't been figured out yet, so different explanations have been made -- some false, some true.
If different isolated groups evolve differently, that validates the claim in the yahoo post. This isn't just a mere opinion, but an a posteriori reasoning.

If you want proof, here are five: http://evolutionfaq.com/articles/five-proofs-evolution

The strong evidence, for the theory that we did evolve from a common ancestor with the chimpanzees, as stated in the evolutionfaq.com link, is that we share 96% of our genes with it.