Where and how the Dao originated is a great mystery. Scientists come up with theories that are nothing more than, well, theories. No one knows, no one will ever know, and even if we do know, someone will be around to argue the point. Instead of trying to figure out the unknowable, it would be a better use of time to manage the knowable. Take the mysterious and make it work for you. Let it run its course and be at peace with the universe.