Good point, you are correct, but (as I'm guessing you're aware) evolution doesn't speak to creation, that's a different theory. I know that it's usually confused, though (I've been in the South myself a few times and currently live in Kentucky), so I generally start by explaining that evolution doesn't say anything about the creation of the universe, Earth, or even the first replicator. Those are covered in alternate theories... I do find the confusion you mention is prevalent.
It's actually harder than that to compare Genesis to our scientific understanding of the universe given that light is created before the sun, and so are plants. There are two creation stories in Genesis and they contradict each other on a number of points. Still if the person you're talking to isn't going to get into the details that strategy can be useful for educating them enough to not want to "fight" against reality.
I like to use Song of Solomon on bible literalists; Chapter 4 uses the phrase "my sister my spouse" on several verses. Interestingly this phrase is also useful in dating the poem as it refers to a late Sumerian tradition. Their Gods marred brother to sister though this was forbidden among humans and as a result of their Gods practice (later adopted by the Pharaohs as they became "living gods") it became romantic to call your spouse "my sister" or "my brother" as the case may be.
You should check out the Sumerian creation myths, though I'll warn you it isn't exactly safe for work...
What do you imagine is the makeup of the Christian population?
People ignorant of science, logic, reason, and philosophy who've either been browbeaten or brainwashed into believing some incarnation of mythology based on bronze-age nomadic Jewish traditions that have evolved over time to incorporate aspects of Zoroastrianism, Mithraism, various Greek and pagan influences, and other cultural artifacts.
That being said the bible is available in over 4,000 languages (http://worldbibles.org/index). I am more familiar with the international spread of Christianity than perhaps you imagine. Various Christian ministry groups heavily emphasize translating and distributing their version of divine "truth" in the native languages of the places where they are proselytizing. Even internationally there are translated bibles, both written and electronic spoken versions, available but rarely used for serious theological study. Indeed I wish it were not true; the more people read that book the fewer people will claim to follow it.
I'd say that evolution doesn't exclude the possibility of a physical Adam and Eve, and also that a physical Adam and Eve isn't strictly necessary to support the doctrine of a 'fall', although some actual physical event - the orignal sin, would have had to occur, otherwise the relevant New Testament passages that refer to it become problematic.
I'm glad you feel that way. Not everyone agrees with you.
I find that most Christians (people in general, really) are startlingly ignorant of the content of the bible and the actual mechanisms and theory of evolution.
Which is, in itself, not that suprising given that most Christians do not have the text in their own language, or are not afforded a sufficient education to be able to read, or are prevented from meeting together and discussing such matters by hostile authorities, or a combination of those factors.
Given that I am discussing American Creationists and given the large number of translations into English this statement is nonsensical. They choose not to bother with it. There are more fun ways to spend their time. The number of Christians I've met who cannot read a bible due to lack of education is very, very low. It's simply not an excuse the vast majority of them can call upon when admitting their ignorance of the book.
I never understood why evolution is such a threat to religion.
It is often considered a threat to Christianity because without a literal Adam and Eve there was no "fall" and therefor we didn't inherit a "sinful nature" from them making the need for God to sacrifice himself, as a child of himself, to himself, to save us from himself, unnecessary. You are correct, though, that it is often literalists who take the most offense to the notion of evolution. I find that most Christians (people in general, really) are startlingly ignorant of the content of the bible and the actual mechanisms and theory of evolution.