"Maybe the Bible really is just the origin story of the Hebrew people and not all people (which would explain where Cain's wife came from). In that case, the flood would have been a local flood, destroying everything in the "known" world and destroying everything YHWH had created, but not everything in existence that had been created by another god or that had come about through natural processes. "
Interesting. This could be very possible. It would make sense, at least.