Denying evolution is exactly the same as denying the nose on your own face. Noses are like fingerprints, only the differences between people is much more subtle.
Centuries ago we had much more bulbous noses, as a species. They were more round and slightly larger than they are today, but as you progress through the generations you see that we have arrived at a more slender, smaller, and pointed nose.
But more importantly, your nose is rarely similar to your parents. The genes that express noses span the DNA in a way that almost any mutation will cause a different nose to be expressed.
Even identical twins will have small differences in their noses, a fact that is usually overlooked. The bridge of the nose, which is shaped by the bone protruding from the skull, is one of the key differences in most noses.
Even as you age, your nose remains the same as you were when you first finished puberty, another odd aspect of this interesting trait. As children our noses almost all look the same, but during puberty they begin to look quite unique.
This is because it is mostly cartilage, which is very pliable in youth, becoming more solid as you age. The end result is the nose becomes the best and most visible example of evolution in action.
This is only one of the many things ignored by creationists, even when it's pointed out to them. It illustrates how cognitive dissonance can make us deny even the most obvious facts just to protect an idea which we were indoctrinated with.