It would seem that the teaching of evolution exclusively violates the provisions of the 1st Amendment to the U.S. Constitution since the Government is not supposed to legislate either for or against any particular religion.
Clearly that's an erroneous interpretation of First Amendment law. For instance, the various Defense of Marriage Acts or the prohibition against bigamy represent official government sanction of "religious" ideas. So religious thought can't be specifically prohibited from being considered as law, I guess.