During my tenure as an active young-earth creationist, I never once heard other creationists accurately describe what evolutionary theory is or how it is supposed to work. Nor did I understand it myself. Creationists often seem familiar with a lot of scientific terminology, but their understanding is filled with gross misinformation. Thus, a host of misconceptions is believed and taught throughout creationist circles, making it almost impossible for actual evidence to really sink in.
There are plenty of comprehensive lists of creationist claims with exhaustive refutations, such as the TalkOrigins archive. Rather than try to replicate those, I will attempt to explain why creationist claims persist in the face of contrary evidence, even when individuals are otherwise well-educated. To do so, I’m going to go over the major areas where creationists get the science itself completely wrong. My list doesn’t represent all such misconceptions, of course. These are the misconceptions I personally recall hearing or using myself. I’ve chosen not to provide specific examples of each misconception from the creationist literature, though they are all easy to find. Citations for my explanations can be found online by anyone who wants to see them; this series is not about any particular facts so much as it’s about how false beliefs are used to support false conclusions.