This question may need some work, but I'll do my best..
I remember hearing a while back that much of the history of India occurred in isolation. Without knowing whether this is strictly true, it got me to thinking about parallel social traits that have arisen independently in different regions of the world.
One of the more interesting social traits is religion. We know that religion is ever evolving, breaking into further sects and so on, and we know that most people throughout history have had a tendency to ask 'why'. So my assumption is that if you take all of the religions which exist today and trace their lineage backwards, you'll find a set of ancestors of 'religious families' which came to be independently of each other.
So what I wonder is:
- Moving backwards in time, can all of the religious families be isolated to their own common ancestor?
- If so, what are the religious ancestors, and in what regions did they arise?