Actually I saw that on some episode of National Geographic. I wish I could tell you more about it. I do have some books on the history of Christianity but if you read alot of History of religion books out there, I'm sure there are plenty of theories floating around about it. Zoastrism (eww..spelling?) is also attributed to some monotheastic thoughts that might have contributed to Judaism concepts as well. Even reading James Michner's The Source (excellent book, one of my favorites) has his theory on the start of religion.
Here's to you as good as you are. Here's to me as bad as I am. As bad as I am and as good as you are, I'm as good as you are, as bad as I am.