The genealogical tables or other records in the book of Genesis which are either introduced or concluded with “These are the generations…” (or similar words) have provided material for many studies. Professor DeWitt, formerly of the Department of Bible in Grace Bible College, Grand Rapids, Michigan, took a look at them in 1976 in the light of recent Near Eastern discovery and scholarly assessment. Though this article is 35 years old, it is still useful for study on this subject today.
In his essay, “Biblical History in Transition”, written in 1957 for the Albright memorial volume The Bible and the Ancient Near East, George Mendenhall wrote of the traditions preserved in Genesis,
However much these narratives have been refracted in the process of centuries of oral transmission, they nevertheless preserve with such vividness and accuracy cultural features which we know to be characteristic of the pre-Mosaic period that scholars today must take them seriously as historical sources, at least potentially. A seemingly endless stream of details has shown us that the cultural milieu of these narratives lies in the Bronze Age, especially the period from 2000 to 1400 B.C…. No longer does the cultural and religious history of Israel begin with atabula rasa in the time of Moses. The religion of ancient Israel did not necessarily begin from scratch, so to speak, but rather it had behind it traditions which show a continuity extending over at least half a millennium. Furthermore, the very beginnings of this cultural continuity took place in a region which we now know to have been in close contact with the high civilizations of Mesopotamia preceding the migrations which mark the beginnings of Israelite traditions, associated with the name of Abraham 
The discoveries which support these generalizations are, of course, the approximately 40,000 clay tablets found at Nuzi and Mari in upper Mesopotamia, at levels dating to the Middle Bronze Age. Mendenhall affirms that the discoveries support the cultural background reflected in the patriarchal material, though the material still evidences a certain refraction which has occurred in the process of oral transmission. The question must be raised, however, as to why we must continue to think aboutrefraction in the process of oral transmission when the very same discoveries which support vividly the cultural scenes and historical accuracy of the narrative also clearly illustrate the development ofwriting and the written preservation of events and transactions. This in turn suggests the creation, fixation and stabilization of the patriarchal tradition during the very same age when the patriarchal history occurred….
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