Everybody knew everything
Distance was not a problem
There is no coincidence
Uh, What?
The anasazi people in Colorado knew what the Mississippian people in illinois at Cahokia knew what the people knew in Mexico. The distance was not a barrier.
The presence of say how to determine the summer solstice in all these places was not coincidence.
(1) Everyone knew everything!
(2) No coincidences! and
(3) Distances can be dealt with.
I err in many ways, Im sure, but I err consistently in those three directions."