It does violate the first ammendment by examination and and legal precedent.
Atheism and Agnosticism
In a 7-2 Court Decision in 1987 in the case of Edwards v. Aguillard, the Court invalidated Louisiana's "Creationism Act" because it violated the Establishment Clause. In his majority opinion, Justice Brennan wrote that the Lemon test had to be used to judge the constitutionality of the Creationism Act:
...the Creationism Act is designed either to promote the theory of creation science which embodies a particular religious tenet by requiring that creation science be taught whenever evolution is taught or to prohibit the teaching of a scientific theory disfavored by certain religious sects by forbidding the teaching of evolution when creation science is not also taught. The Establishment Clause, however, "forbids alike the preference of a religious doctrine or the prohibition of theory which is deemed antagonistic to a particular dogma." Because the primary purpose of the Creationism Act is to advance a particular religious belief, the Act endorses religion in violation of the First Amendment.
Now is the winter of your discontent!
-- Stewie Griffin