I just completed tenth grade a couple weeks ago, and I took a biology class which sounds remarkably similar to the one your son had. I anticipated the evolution unit all year, hoping for some debates and "new stuff", and for my teacher to explain what evolution really is (favorable mutations being passed along) and isn't (a complete explanation of all life and completely incompatible with creationist views).
However, the unit was decidedly anticlimactic.
Several creationists were in my class, and my teacher never hit home the point that evolution doesn't nullify their ideas. Therefore, they refused to accept any of it and are still ignorant as to evolution. They also asked the question which gives me a headache every time I hear it - Why isn't creationism taught in schools?
The class, besides antagonizing the creationists, was simplified to the point of being what everyone already could get from common sense - disregarding those who refused to accept it because it was called "evoution", of course. All we talked about was DNA passing through the generations. I was hoping for talks about evidence of evolution (geographic similarities but completely different wildlife, penicillin's relative inneffectiveness nowadays, etc) but those were missing, as well.
I think that it would be interesting for classes to make use of what some students already know about evolution and hold informative debates. I read the Origin of Species in ninth grade and have watched shows and read web information regarding evolution, and feel that I could have contributed to the class's understanding if I'd been able to make a non-instigatory statement.
Even without class discussions, I feel that evolution is an important topic for teens to be introduced to. It gives them a chance to form their own opinions and find out the truth about evolution. Many people have gross misconceptions of the topic.
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