Once you allow for an old earth and evolution of humankind, I think there are ways of looking at Adam that are a combination of literal and allegorical elements that do not conflict with scientific evidence (see my July 25 post on “How do theistic evolutionists view the fall of man?”). My problem is with the flood. I don’t have a problem with the idea that it was a local flood - I understand that the translation of “kol erats” does not really indicate the entire globe, just the “land” which was known to Noah. If there was a catastrophic local flood, then scientific evidence must show a major population bottleneck. Science does show that there was a major population bottleneck between 50,000 and 100,000 years ago, bringing the homo s.sapiens population down to between 3,000 to 10,000 individuals. It is not too hard to consider that it could have been 8 individuals who carried 5 DNA lines (Noah and his sons plus 4 wives).
I don’t even have a big problem with getting representative animals in the Ark, if they were only the subset of animals that were in the region of the flood.
However, this means that the flood happened about 50,000 or so years ago.The problem with that is that scientific evidence shows that humankind was not nearly advanced enough at that time to build a huge ark. How do we solve this problem?
I realize that one potential solution would be to move the flood to much later in history, but there is no evidence of a big population bottleneck to match. Besides, by this time humankind would have been disbursed around the globe. You would have to assume a smaller flood which only wiped out peoples in a regional area, not all people or even a sizable % of all people… At any rate, that scenario has some significant problems with it as well.