If you gave it some thought, I'm sure you would see that a literal Adam and Eve are entirely consistent with biological evolution. But since one's opinion on that matter is not what determines your salvation, it's not really important.
When I was a YEC I don't think I was able to really conceive of how the two could come together. Years later, and now looking at things; it's really not problematic at all. There are still complications that I don't pretend don't exist. But on this specific matter, it's hardly difficult to conceive of the possibility that at some point there is a clear distinction between the "mere animal" and the "rational creature". When this happened, exactly when--we might say--Adam and Eve lived is probably not the sort of thing we're going to know. But this isn't particularly difficult: from a purely evolutionary perspective at some point hominids became not only clever apes, but creatures capable of deep, complex self-reflective thought, creatures of reason, moral agency and moral reflection. That capacity for moral thinking, for deep complex self-reflection and contemplating one's own existence in the world is not something my dog has, it's not something even our weird cousins the chimpanzees have (who are, let's not pretend otherwise, incredibly clever and still incredibly intelligent).
I don't just have the capacity to do something wrong--I can recognize that what I did was, indeed, wrong. That my actions introduce something deeply problematic to the world--my actions actually wound, and I know they do--and I do them anyway.
There's clearly something very different about me--and all of us human beings--from all other animals. And I'm not convinced that science and a purely naturalistic methodology is capable of truly plumbing the depths of that. I am very clearly more than just the sum of my parts, I'm more than just an assemblage of atoms, more than bio-chemical machinery, I'm more than just the grey-matter between my ears, more than just a series of input-output responses to sensation and external stimuli. I have a
soul. I'm me, I am myself. And I am a me that meets you, and you are you--you are yourself, another
person. Personhood extends beyond material demonstration--but arises from something much deeper. And, as a Christian, I think the very clear answer, given to us by divine revelation, is that our own personhood is a gift from our Creator. He made us in His image.
So there was an Adam and an Eve, and we're all descended from them. And that doesn't negate the reality that, as we observe the fossil record, as we observe and study genetics and molecular biology, we see that all living things on this planet share common descent, that human beings share a very real genetic and biological common ancestor with chimpanzees, with all the other great apes, and that we see all manner of now extinct hominids who left behind their remains, fossils and even tools.
How all this works out to the jot and tiddle is, probably nothing we're going to figure out. But what we receive by Divine Revelation; and what we receive by natural disclosure are not two contradictory stories;
they are both true stories. The Good Creator God, if we truly believe He is the Good Creator God, did not create a false universe, a lying universe, but a good and truthful universe. So if something is, indeed, objectively true about the universe in what the universe "tells" us through its own self-existent reality (e.g. I see a mountain, there really is a mountain, I see a river, there really is a river, etc) then it's true. To suggest otherwise indicates a willingness to believe the old Gnostic lie; that the material world is at best an illusion created by a false sub-god or at worst an evil prison created by an arrogant tyrant evil false god. But the Christian Confession is straight to the point:
We believe in one God, the Father Almighty, Maker of Heaven and Earth, of all things seen and unseen.
-CryptoLutheran