Almost all of the Genesis stories are holdovers from Mesopotamian myths and legends. I don't believe anything in Genesis really occurred. At best they are allegories that attempted to describe the origins of life and the universe to illiterate Bronze age peoples. At worst they are plagiarisms from the creation myths of the Sumerians and Babylonians.
I've recently been discussing this very thing on another thread.
We differ in at least two places. I don't believe they are myths at all and I believe the creation story was taken by Cain to Babylon. It was they that copied the stories and corrupted them. Genesis is true but has to be read deeply for that truth.