Is All Mythology Created Equal?

Take a moment and put aside right and wrong, and truth with a capital T, and just hear me out.

Maybe the better question is this: Does all mythology come from one source? One missing link? And is everything else just variations on those same themes? Is that missing link something embedded in our consciousness? Is religion, like some evolutionary theorists suggest, an impulse which we bred into ourselves, therefore making mythology some instinct, some bizarre shared memory with shared meaning, so that the ideas, tropes, stories contain that same thread, no matter where on earth it's found?

Or is it as simple as this: the culture and supposed religion of a megalith people. (And regardless of the title of Wikipedia's entry, this culture stretched all the way to the far east--though there is a bizarre gap in the middle.)

How did so many similar stone works appear in such disparate locations without some communication, some GLOBAL communication to spread the word, the story, the culture, the knowledge of how to even build them. And if that culture could exist so persistently around the world, creating such similar and incredible works, couldn't they also have been responsible for the spread of stories and tropes in mythology like The Flood? Could they be pre-biblical tradition? Pre-babylonian tradition? Tradition which inspired both the bible and the greek myths and the stories of other gods and godly acts around the world?

What is the simplest explanation? That each group of people independently moved in a similar direction, created similar works, or that there was some thread, some culture connecting them?

From my superficial and lazy research it looks like the Assyro-Babylonian tradition influenced both Abrahamic (for my purposes, Biblical) and classical mythology.

But did those stories originate from the Babylonians and the Assyrians or the Hittites? Or is this just the first evidence we have of them? And if only some Babylonian aspects were assimilated by the Biblical tradition, where did the rest of the Biblical mythology come from? Where did the rest of everything come from for all other mythologies? For example--the flood clearly has Babylonian roots, but what about the sacrifice of a child, saved at the last minute by the god who requests the sacrifice, which appears in both Classical and Biblical mythology? Where does that trope come from? Where does it originate? Is that also Babylonian or Assyrian?

Possibly I'm behaving like some kind of conspiracy theorist with an obsession to connect the dots of religion from one mythology to the next. Perhaps it isn't as complicated as any of this. Perhaps someone, somewhere, was just charismatic and creative. Maybe he lived among the Babylonians for a while, and then wandered down to Greece, bringing his stories with him. His personal mythology. And maybe that's all it took.

But it sure seems more real, more meaningful, if it's something more.