This might be something some of you should read:
As is well known, traditionally these verses of Genesis have been understood as giving details left unattended in the sketchy presentation of creation in chapter one. This way of reading also assumes that the whole of the Pentateuch was written by Moses in the XV century B.C.E. Such reading is still defended by fundamentalists, but cannot stand before the evidence in the text. For more than two centuries biblical scholars have reached a broad consensus and identified in the text sources which were edited to form the extant Pentateuch. This editorial work was carried out by priests of the Second Temple between 450 – 400 B.C.E. The literary sources uses by the editors contained different versions of the same events as well as narratives peculiar to one tradition. In Genesis, Exodus and Numbers the editors were primarily dependent on two sources, while a third one less extensively used can also be identified in sections of the text. To identify these sources scholars study the vocabulary, the name given to God and to significant places, the literary style, the identity of the actors, the theological point of view, the metaphors used to describe the relationship of God with Israel, etc.
Like the whole thing, at the link above. Seriously.