Been thinking up some scenarios I thought would be interesting to see what would happen.
So my most recent thought up one, is what if the civilization situation of Eurasia and the America's were switched. The America's become the cradle of civilization, while Eurasia remains more or less tribal. Instead of the major megafauna becoming extinct in the America's, it instead becomes extinct or never spreads to Eurasia. Might have to figure out what to do with the lack of tin, but maybe tin will also be more widespread in America or something.
My other one, was what if an apocalypse that only takes away humans were to occur, and then after X amount of time humans are re-introduced with an entirely clean slate. What cultures and religions would appear? Would there be some kind of worship of say the Statue of Liberty? The Eiffel Tower? Etc? Just something that seems like it would be interesting to think about what would happen.
Disclaimer: Yes I'm fully aware that there was some civilizations in the America's, however what I'm thinking of is much more widespread civilizations becoming widespread fueled by presence of animals like horses and American Camels. Also, I like to study religions other than my own (Asatru)