Genesis: incest?

Now, let me remind you of the story of Genesis. It is Christianity's story of how we "became". Obviously, being an Atheist (with Agnostic tendancies, though) I don't beleive this and I feel Charles Darwin and his research is correct — as in; the survival of the fittest.

In this version of the World, after God created it in one week (with rest!) he placed a man, Adam on the Earth. In the Garden of Eden. Paradise. He could eat all the fruits, and so on. But he was told not to eat from one tree. He then got lonely, yadda yadda, and then when he slept God took one of his ribs and made a woman, Eve, from it.

She ate the damn fruit! But let's forget that part. That's not important. What I want to focus on is how Adam and Eve populated the World.

Together they had two sons, Cain and Abel. Okay, that's fine. A man and a woman have sexual intercourse and then there's a kid. Forgetting how Adam knew how to deliver a child (which is something to think about in itself!) and they both were A-OK; then what happened?

We have a family history that goes like this: God makes Adam who marries Eve (parent). They have Cain and Abel (child). So that's a mother, a father and two sons. So how does that combination populate the Earth? Maybe it's Naïve of me to question this — I haven't read the Bible. I have only researched this story on Wikipedia after working out some flaws in Religious Education last Tuesday. Possibly, some Christian will read this and provide an explanation citing the Bible.

Back to my argument, though: so let's check our options. Either:

Abel or Cain has sex with their mother, Eve. This is incest.
Or, Eve has another child, a girl, and either Adam, Abel or Cain has sex with this new girl. This is also Incest.

And we're all sure of what Incest is, right? It isn't tolerated in either moral situations, nor biological ones — usually what many people call "mutants" would be born. Deformed human beings.

I'm sure this has been dealt with before — but I'd sure like to hear the defending argument! Either people are not well-informed enough about another counterpart to Adam and Eve (as in, another God created being) or we are all having sex with our extended families!

I wonder how Darwin would use this to his defence? (Digg)