Maybe, but probably not...
Who was the wife of Seth, son of Adam and Eve? His sister. You know that later, Sarah was Abraham's sister, as well as his wife, right? Prohibitions against incest did not come until later, under Moses I believe.
According to the Genesis story and Hebrew legend, there was much sexual perversion and comingling with demonic seed among the antediluvians... Noah's family was untainted. It's likely that the wives of Noah's sons were closely related.
I've heard this speculation before, and I'm not doubting it, but I feel that the first part of Genesis 6 is rather obscure, and could mean any number of things, including God chose Noah because he was righteous.
Ok, here's something else to think about. God made two individuals. Obviously humanity had to come from these two, and then from their children. Adam and Eve would have had to of been quite different genetically in order for their children's children not to have problems. If this is the case then, God must have created genetic diversity into the human race as a way to avoid problems with the genetics of bother/sister pairings. In this way it still goes against the data, people should still have more genetic diversity.
Another possible idea I just thought of, was that there was no such thing as a recessive trait until the fall of man. Man's gene's were perfect, but became over time more and more imperfect due to exposure to mutagens. Imagine the possible amount of muation a germ line could take up when the people were living 900+ years. This could possibly help explain the genetic diversity we see with the chimps..