Random thought here: The evidence for evolution is overwhelming, but you do actually have to educate yourself about some of that evidence. You can't just look out your window and deduce, say, some of the really striking evidence coming from molecular biology that is helping to clarify the tree (er, tree-ish, allowing for horizontal gene transfer) of life.
But the evidence for common descent? I mean, are you kidding me? First of all, anybody who denies that humans are a type of ape, I mean.. Really?!? Have you, you know, like looked at a chimp or an orangutan or anything? You didn't notice that they look almost exactly like us? Second of all, the Satan is a Dick Theory notwithstanding, the frikkin' fossil record... I mean, I guess I can understand this one because many Creationists studiously avoid ever acknowledging the incredible wealth of transitional fossils that are constantly being paraded in the media as the latest example of "The" missing link. But come on...
That such incredible change could have taken place through natural selection and genetic drift alone, that's hard to comprehend, I get that. A lot of that I think is because our ability to conceive of the time scales involved is very poor (I have found that when thinking about big numbers, there's a point where I start treating exponential growth as if it were linear, e.g. I have a tendency to think that the order of magnitude difference between 10,000 and 24,000 is on par with the difference between 10110 vs. 10124, but of course that's absurd -- and I know how absurd that is, and yet that's still how I think about very big numbers instinctively, so imagine how bad it is for someone who is less familiar with large quantities). But in any case, if somebody accept common descent, but thinks there needed to be some kind of outside force to help natural selection along... well, they're still wrong three ways from Sunday, but that's a mental error I can grok. You have to actually look for the evidence to understand what is wrong with that argument.
But denial of common descent? Denial that we are, plain as day, primates? Don't get it.