Okay, it's perfectly reasonable to disagree with the theory of evolution for scientific reasons (by the way: don't say "it's just a theory." GRAVITY is just a theory, okay? 'Theory' doesn't mean 'half-assed guess'.) But to disagree because it conflicts a creation story written thousands of years ago and because it means you'd have to acknowledge you're not as different from animals as you'd like to be? No. No no no no no. This isn't about freedom, people. It's just another excuse to force your religious beliefs on others.
And hey, if you're teaching alternative theories, could you at least get a little diversity in there? Have one unit on Christian beliefs, and another beginning, "So there was this giant turtle..."