Who is "they"? This seems like an argument against organized religion because of religious hegemony in certain cultures.

Certainly people _do_ gravitate towards moral mythology whether they like to admit it or not. The popularity of superheroes in North American culture speaks to this in modern times, most of which appear to be stories about defeating evil in ways that parallel those of ancient myths.

The argument is that the Bible is a really great myth because it survived for so long. The fallacy in that argument is that the Bible did not survive as a myth, it survived as a written record of events.

The Catholic approach, at least, is that the Bible contains a variety of literary styles, and so it's both. Some books are records of events, some are letters, some are myths in the Joseph Campbell sense of stories that are meant relate deeper truths about human nature and mankind's relationship with God. Most of the people who did this preserving over the centuries didn't subscribe so much to literal-minded fundamentalism.

The Catholic approach doesn't allow for swapping out biblical myths for other myths, which means that the Bible wasn't competing as a myth in their cannon either. If there was a form of "natural selection" operating on it, it was not operating on it as a myth. However I grant that "they thought it was true" is a vast oversimplification of the many motivations that people have had for printing copies of the Bible - which can include purely financial ones!

Ah, I think I see what you mean. Yes, most of the curation of the biblical canon was settled by the 4th century or so, and after that it came along with the religion as a fixed entity. But that doesn't mean there wasn't some natural selection of myths before that, especially those that had already been around for a long time before they were written down. Some weren't exclusive to Judaism; compare Noah to Utnapishtim in the Epic of Gilgamesh.

I don't think 3rd century Christians were comparing different accounts and selecting them on the basis of how well they would function as allegorical myths. I could be wrong, but as far as I know that is a modern invention, developed to reconcile the supernatural elements of scriptures with the naturalistic worldview that developed during the enlightenment. To understand the setting of early canonization, you have got to picture a world of persecution, faith and martyrdom that is hard for us to imagine in our liberal, secular and comfortable world.

I understand that the view of the Bible as a product of natural selection is a way to transpose the belief that it was not made through purely human forces to a philosophical system where all nonhuman forces are natural. However, the argument for relevance to modernity is severely weakened by this rebasing. It is not the present environment that determines the shape of the animal, but the historical environment, and while the survival of a species is a testament to its adaptation for the historical environment, it is not a testament to its adaptation for the present environment. Since the historical environment was a combination of true faith, and later illiberality, there is no reason to think that it should be adapted for the modern environment of the allegorical view and religious freedom. That is why I do not think the naturalistic view works as a justification for the providence of the scriptures.