Refpunk: And which of these "theories" were all consistent with one another like the flood story is?
These aren't theories. These are ancient stories, just like the flood story is. In this case we are talking about stories in which human beings have animal ancestors.
These tales are as internally consistent as the flood story is, for the reason Dr Adequate just noted.
If you really believe ancient folk tales are important sources of scientific information, as you say, you will now begin seriously entertaining the possibility that human beings had animal ancestors.
And, of course, being the earnest truth-seeker that you are, you will do your best to learn more about the many folk tales that exist in the world before dismissing any of them unheard. You want to glean them for the information they have to offer.
It's a fascinating area of study. I wish you well in your research.