I'd love to see this done for some of the components of the major
religions. Like someone (sorry, deleted it after reading it) suggested,
maybe we could map out a few parts of various meta-memes.
Here's the US rail gauge story (warning, possible urban legend):
The US Standard railroad gauge (distance between rails) is 4 feet
8.5 inches. That is an exceedingly odd number. Why was that gauge
used?
Because that's the way they built them in England, and US
railroads were built by English expatriates.
Why did the English People build them like that? Because the
first rail lines were built by the same people who built the
pre-railroad
tramways and that's the gauge they used.
Why did they use that gauge then? Because the people who built
the tramway used the same jigs and fixtures that they used for
building wagons which used that wheel spacing.
Okay! Why did the wagons use that odd spacing? Well if they tried
to use any other spacing the wagons would break on some of the old
long distance roads, because that's the spacing of the old wheel ruts.
So who built those old rutted roads? The first long distance roads
in Europe were built by Imperial Rome for the benefit of their
Legions. The roads have been used ever since.
And the ruts? The initial ruts, which everyone else had to match
for fear of destroying their wagons, were first made by Roman War
Chariots.
Since the chariots were made for or by Imperial Rome they were all
alike in the matter of wheel spacing.
Thus we have the answer to the original questions. The US
standard railroad gauge of 4 feet 8.5 inches derives from the original
specification for a Roman war chariot. Specs and Bureaucracies
live forever. So next time you are handed a specification and wonder
what horse's ass came up with it, you may be exactly right. Because
the Roman Chariots were made to be just wide enough to accommodate the
back ends of two war horses.