Not a metaphor question. I mean literally: Norse mythology has Jormungandr, ancient Mesopotamia has Tiamat, China has dragon kings, the Aztecs have Quetzalcoatl, Aboriginal Australians have the Rainbow Serpent. Cultures that had zero contact with each other. Did they all independently invent the same creature, or is this thing old enough that it got inherited from some shared ancestor population before humans spread across the earth. And is there actually a way to test that, or are comparative mythologists just pattern-matching and hoping.
as someone who spent his career in biology and not mythology, I would really love a proper answer to this one. it's the kind of question where I know enough to be confused but not enough to even guess.
the serpent specifically is the one I can never explain away. I can construct a diffusion argument for almost any other cross-cultural parallel but Aboriginal Australia breaks it every time. There was no contact. So either the creature is old enough to predate the migration out of Africa, or humans keep independently inventing giant serpents for reasons nobody has satisfactorily explained to me.