I did a whole class semester on this stuff.
I believe the Bible is a religious book, not a science book, and it was never intended to be used as such. Unfortunately many Christians seem to think the Bible is God's documentary on the universe, when its God's documentary on his love.
There are numerous clearly metaphorical passages in the Bible, yet some Christians refuse to believe the Creation story is anything but fact. I forget specific examples right now.
Lots of scientific evidence from DIFFERENT, INDEPENDANT SOURCES points to an old earth. Little, if any, evidence supports a young earth.
By an extension of the above, literal creation should not be taught in schools because it has no scientific evidence to back it, and thus is not fit for a science class. It could only be taught in a religious context.
Plenty of Christian scientists believe in evolution and do not see it conflicting with the Christian faith.
The Christians who insist on a literal creation story from Genesis do so because they believe it is a cornerstone of their faith. As a Christian I believe it is not, rather the love, death and resurrection of Jesus Christ to save us from hell is the single, sole belief of Christianity that everything else builds on. Genesis' story of the fall of man is an important part of this but occurs after the creation story.
Christian children are not taught the true facts about evolution, only that it is wrong and they should not listen to it. (I speak from personal experience.)
Christianity and evolution in no way conflict, infact I believe evolution shows a more powerful God than a 6-day creation. I think of it this way: God snapped his metaphorical fingers and we got the big bang. Not only that, but everythign in the bang was arranged in a specific way so that our solar system would form, earth would form, life would emerge, and humans would evolve. All planned in an instant, all executed in an instant, and God sit back and let his tapestry weave itself! (That's my personal view.)
Virii are a modern proof that evolution and natural selection exist. Any doctor will tell you that if you have a virus, medicine of some sort can help kill it. If you don't take enough, the virus won't die fast enough, and may become immune to the medicine. This happens through natural selection, where random mutations in the virus make it immune, and those virii survive the purge and then replicate with their new DNA.
HIV/AIDs treatment sees this alot. New treatments involve taking patients off medicine completely for a bit. The virus now mutates and replicates and soon is no longer resistant to the medicines it was before (as it no longer needs that gene to survive so virii without it can live and replicate the lack-of-gene). Then, a cocktail of different treatments can get the virus more under control than it was before removing the medicine.