Teaching creationism as an alternative to evolution undermines biology. When you look at an organ, you have to see what it does and why its there. Simply saying "because god made it so" blocks the progress on knowledge and keeps us from understanding ourselves. Furthermore, the creationist time period blocks new discoveries in geology. All this is apparent to many. But there are those groups who feel threatened by this. In fact, they want to legitimize superstition to compete with science. So why are so many American Christians like this?