I recently had a discussion with a creationist at youtube. I think I've found the right method in dealing with them: Stay calm and rational, and after four or five responses, wish them the best, tell them you'll have to agree to disagree. Recommending a book never hurts either. I always try and recommend Ken Miller's "Finding Darwin's God"; or even better, a christian evolutionist website like Answers in Creation.
The Guy made several claims: The geologic column doesn't exist in its entirety anywhere in the world, bent strata indicate the rock was laid down catastrophically, and so on and so on. What bothered me is that he accused talk origins of making false claims, and insisted that there really was no complete geological column in one location. Luckily, talk origins always provides enough information for me to be able to check out their claims from other (and often better) sources. Sure enough, it does exist in one place. It disappoints me that creationists will swallow so much malarky from one or two creationist sources without bothering to do real research to get the facts.
Anyway, at one point we discussed human fossils. I asked why it was that humans are absent from all but the very top of the geologic column. He directed me here. There are several things about this article that are very hypocritical and downright stupid:
The first issue to consider is what we actually find in the fossil record.
~95% of all fossils are shallow marine organisms, such as corals and shellfish.
~95% of the remaining 5% are algae and plants.
~95% of the remaining 0.25% are invertebrates, including insects.
The remaining 0.0125% are vertebrates, mostly fish. (95% of land vertebrates consist of less than one bone, and 95% of mammal fossils are from the Ice Age after the Flood.)1
The number of dinosaur fossils is actually relatively small, compared to other types of creatures. Since the Flood was a marine catastrophe, we would expect marine fossils to be dominant in the fossil record. And that is the case.
Actually, sediments are usually deposited in water, so it isn't any surprise that most of the fossils we find are marine organisms. We certainly don't need Noah's flood to account for it! Another thing about this that is totally inconsistent is that this guy makes a huge deal out of only a few vertebrate fossils existing, yet creationists are constantly demanding finely graded chains fossils leading from past organisms to present (on occasion we actually find these, but they are rare and of course this only happens under the right conditions).
The article goes on to make speculations and invent excuses about why no human fossils exist in deeper strata. I stick to my original objection: It makes no sense for humans to have missed fossilization for the first 3 or 4 billion years of the fossil record, and then to have started fossilizing by the thousands around the Pliocene. That is, unless they didn't exist back then.
By the way, check out this link for a hilarious creationist take on the geologic timescale.