It's the only thing people seem to be divided on in education. People don't get upset in math class because the teacher is using y=mx+b. People don't get upset in political science class when they talk about the Constitution. They don't get upset in Literature class when they teach the structure of a Shakespearean Sonnet. Even other things in science are undisputed. Nobody's mad over the Periodic Table. Nobody's mad over Cell Theory. Nobody's mad over DNA. What is it about Evolution, specifically, that gets people all wacky?