sir82 is a bit mistaken here... The first 11 chapters of Genesis are not "a mishmash of a bunch of separate . . . oral traditions." The whole Pentateuch is. The modern scholarly consensus is that the Torah was not written in part or in whole by Moses or by any other single person. It is a composition of different written sources (not oral traditions) which then were based on oral traditions.
There is a hypothesis called the Documentary Hypothesis which states that the Pentateuch is composed of four separate written sources named J, E, D, and P. However, scholars today have varying views in regards to that hypothesis. Some say that there were more sources, some disagree with the dating of these sources, some say that J and E were not separate sources, and on and on it goes... Basically, scholars have different views, but everyone agrees that the whole Pentateuch is a composition of different sources.