Teaching evolution is a non-issue, just present the scientific basis and let the kids decide for themselves if the need a different belief system. What handicaps public school teachers is the inability to present the creation argument for comparison.
And what should really give teachers difficulty is trying to convince students that some people are genetically disposed to be homosexual because it is obvious that homos cannot breed and pass along that genetic trait. If blue-eyed people could not breed, there would be no blue-eyed people, and so it would be for homos, if they really were “born that way”.