Evolution, the combination of such processes as Natural Selection, Sexual Selection, and others, is the subsequent collection of scientific processes that eventually change one organism into another. It is important to discount a few widely held myths here that Creationists
often erroneously use to discount Evolution, bringing up half-baked ideas about how one or more "facts" disprove evolution, without bothering to actually know what they're talking about. However, a little care and attempt at education can easily clear up these mistakes:
1.) Evolution does NOT necessarily dictate that animals (or plants, or fungi, or whatever you fancy) must evolve into something more complex. If all animals over the size of cockroaches were wiped out tomorrow, that would be a form of evolution: the Cockroaches and smaller animals would be the surviving species, and "Survival of the Fittest" (a common saying used in evolution) would hold true.
2.) Evolution does NOT, I repeat NOT suggest that humans "magically appeared from crawling fish". Evolution takes time. HUGE amounts of time. We're talking about half a billion years here (~500,000,000)for the total evolution from the first protochordates into the modern Homo sapiens. Not a couple days. Not even a couple centuries. This time span is so long that it's often hard to comprehend. The changes were gradual, as some random "mistakes" in our DNA made some animals better able to adapt, and others not as able to adapt. It is NOT like throwing sand in the air and having it come down as a sand castle. It is, however, like sprinkling little tiny bits of sand here and there - sometimes a grain at a time - and eventually building up to a sandcastle. And sometimes having bits of the sandcastle knocked down.
3.) Species that died out, such as Homo neanderthalis (Neaderthal Man) are not counterexamples. In fact, it shows that two different species, with two different natural "sets of equipment", have different ways (and thus chances) of surviving or outlasting eachother. We and Neanderthals DID stem from the same common ancestor. However, whereas Neanderthals had stocky, tough, but not to bright build, we went the lean and brainy root. That was fine for a little while, but soon we outcompeted them, and they died out.
4.) In regards to the comment above that some species were found in the wrong area: The earth moves. Ever see a volcano? An earthquake? Rocks don't always just sit there.
5.) Any educated biologist will not respond by saying "oh, you're right, evolution didn't happen."
Bill: But monkeys and fish look real different, so evolution must be wrong! Fish change into monkeys suddenly? LOL!
Jill: That's not really what Evolution says...