What are two disparate phenomena that surprisingly have the same or at least a related explanation?

This map shows the locations of ancient river civilizations. which letter on the map shows the location of mesopotamia? letter a letter b letter c letter d mark this and return save and exit next submit

Which of the following best explains why california has more catholics than any other state? california is home to a large population of asian immigrants, and many asians are catholic. california has very little religious diversity. california has a large latin american population, and many latin americans are catholic. the catholic church is based in california.

What directive in source a might have been at the root of the action described in source b?