A Reader asks, "I was asked by a friend how the world got populated if Adam and Eve were only two people and after the flood just Noah and his family existed. Wouldn't this mean that someone had to commit incest? This is one of those questions that I don't know the answer to. Personally I believe this to be more of a legend/myth/story than literal meaning."
Those are really good questions. We know through modern genetic science that if the human race were reduced to two people like Adam & Eve or one family like Noah, that the lack of genetic robustness would likely lead to the eventual death of the human race. The only real way around this would be to insist that God was constantly fiddling with individual genetics at this stage, which seems bad initial design on God's part.
Of course, the writers of the Bible didn't know much about genetics beyond the traditional taboos on incest (which they ignored in these cases. Hmm.) When they were codifying the oral tradition of these stories, which had probably already existed for a thousand years, they didn't ask themselves questions about chromosomes or DNA. In fact, they didn't generally ask scientific questions, which is something we have to keep in mind.
When analyzing story, whether sacred or secular, you always have to keep in mind what questions the writer is trying to answer. In the case of Genesis, the writer is trying to answer a theological "Why?" He is not trying to answer a scientific "How?" The point of the creation narratives are the order - that all that is created is good and that humanity is very good. The question of the story of Adam and Eve is "Why are we separated from God?" and the answer is an exercise of free will against the purposes of God. The point of Noah is actually to explain the rainbow, which we look at as a throwaway since we have a scientific explanation, but would be VERY significant in a pre-scientific culture. (Think about that - if you didn't know about refraction and the spectrum, what would be the meaning of a multi-colored weapon appearing in the sky after rainfall?)
Pre-enlightenment cultures simply thought very differently than us. Truth was not considered something provable by scientific test - it was something found in story. You will find Jewish commentators around Jesus' time talking about the meaning of a "day" in the creation narratives. It does not appear that rabbis then (or now) thought that a day had to mean a 24-hour period.
We have a hard time getting our minds around this because of the scientific world we all live in. We think that something needs to be 100% verifyably, factually accurate in order to carry truth (see my entry, The Heresy of Literalism for how this has effected modern Biblical interpretation.) For the vast majority of the history of Biblical interpretation, if you were to show someone proof that something in the Bible was not factually true, they would say, "So what?" and then tell you what the more important meaning of the passage was. Factual accuracy is a modern obsession.
No, I think you've hit the nail on the head. The stories of Adam and Eve and Noah are not histories in the modern sense. They are "Fairy Stories" in the sense of Tolkien and Lewis (see Feast of CS Lewis) that carry a meaning that scientific fact cannot. The fact that they are fictionalized, or semi-fictionalized (almost all Middle-Eastern cultures have a flood narrative, so SOMETHING must have happened) does not lessen their authority in teaching us about the way we relate to God and each other. In fact, I think they are MORE effective because they (should) put us in a place of suspended disbelief about the facts so we can concentrate on the questions that the writers are really working on. To obsess about the factual accuracy of scripture, either to prove or disprove its value, is to miss the entire point.