Evolution is clearly at work, though we don't fully understand it yet (or rather, how it's capable of producing some rather incredible results). Really, while it can be hard for us to see it in our sort of "macro" world of large, complex animals and the like, evolution can literally be observed by the minute among bacteria and viruses.
It always seemed like efforts to prove the concept of evolution to people were wasted by focusing on the animal kingdom. Just refer to the new strains of viruses and such that are always arising, as they didn't just appear out of thin air.







