I find it extremely hard to believe that evolution didn't happen. There is plenty of evidence. For example, we have lots of remains of past human species, like Homo Erectus and Neandertal. There is some evidence (that I don't really understand -- I'm not an anthropologist) that Homo Erectus evolved into modern man and Neandertal didn't.
Also, look at viruses. Viruses are constantly mutating and adapting. Look at the Bird Flu -- everybody is afraid that it's going to mutate and begin to infect humans. If evolution doesn't exist, that wouldn't be an issue. Same goes for antibiotic-resistant strains of certain diseases.
Next, look at animals. They have evolved defenses that they didn't have, and I'm sure I've read that there's evidence. They have a certain color, certain instincts, and certain defenses that they haven't always had. As one example, look at whales. Whales used to be land animals. Whales have the remains of legs, and archeologists have traced back whales' development to a wolf-like animal.
Evolution definitely exists, to some extent, in nature. And I think that it applies just as much to humans.
A lot of people attack evolution based on the fact that it's a 'theory'. And that's true, it's a 'theory', but so is everything else in science. There are very few actual laws, anybody who's taken Physics knows that.
And incidentally, this survey was based on per-country statistics. The majority of Americans don't believe in evolution, whereas the majority of the rest of the world does. And I think that's the definite proof that everybody is looking for -- if Americans are the only ones who believe something, then it's probably wrong. :-P