It is perhaps true that Noah loaded some livestock onto a boat, and the myth grew into the Biblical tale. Is every human alive today a descendant of Noah and his family? That is quite unlikely. I would think that geneticists would have the ability to determine that. Thee are a lot of variations between human populations on this planet: Eskimos, Chinese, Dravidians, Pygmies, Berbers, Australian Aborigines, Laplanders, Ainu, and of course Europeans, Middle Easterners, and many different African groups: all descended from eight individuals: Noah, his wife and his three sons and their wives.