I am a Christian as well, and I do take Genesis literally and historically. I also subscribe to the scientific view that the earth is 4.5 billion years old and that the evidence for universal common ancestry is overwhelming.
"WHAT?!?!?" (you may be thinking). "Doesn't a literal interpretation of the Bible require a belief in 6-day creation?" No, in fact it does not. A literal interpretation of most
modern English translations of the ancient Hebrew text of the Old Testament may require such, but a scholarly treatment of the original inspired text can reveal possible alternate translations that may maintain the historicity of Genesis without conflicting with the foundations of evolutionary theory. Dismissing the first book of the Bible as "myth" or "parable" may be one convenient way to reconcile Christian faith with evolution, but I think many Christians may be giving up on the historical accuracy of Genesis too quickly.
To cite one example that attempts to reconcile science with the creation account, Christian geologist Glenn Morton presents an interesting theory at
www.glenn.morton.btinternet.co.uk/person.htm. I'm not sure I completely agree with his theory, but it's worth considering. There are many others out there that hold just as much merit.
I believe Christians should be open to the possibility that some middle ground exists between "literal" 6-day creation and the "myth" of Genesis. To find such a stance is not an easy or straightforward proposition, but the Bible never says that studying God's word would be easy.