Peter Enns has written a short essay providing a “descriptive historical survey” on the evolution of the Pentateuch titled “When was Genesis Written and Why Does It Matter?”. You can access it from the BioLogos website here. The thesis is as follows:
“The Pentateuch as we know it was not authored out of whole cloth by a second millennium Moses, but is the end product of a complex literary process—written, oral, or both—that did not come to a close until sometimes after the return from exile.”
Enns makes some good observations (nothing radically new, hence a “historical survey”). I think it is a worthwhile read and I’d be interested to hear the opinion of any student of the Old Testament who has read it.