Adaptation where you develope some traits or lose some traits, but still remain essentially the same species wasn't the type of evolution people were arguing over I thought. If I'm mistaken, I'm mistaken(Was that what you were describing?).
Humans might not live long enough to see species-into-another-species type evolution, but we do have the technology to record images and biological data to pass from one generation of observers to another.
My concept of a theory may not be as sharp as that of a lot people here, but would I be wrong in saying that a theory is a possible, plausible explaination of a known fact or relation between known facts, while at the same time NOT being a known fact itself(the theory)? If that's the case, the part about not being a known fact itself is what leaves theories fair game for naysayers. That's why the nutjobs are so loud(Fortunately, no one has to agree with THEM either!). To use
>>1's question, how do you shut them up? I currently can only think of 2 ways: Show a theory to be irrefutable fact, or challenge them to offer a better theory based on known facts.