It's kind of crazy that almost nothing happened in Africa and Americas
Discussion
A lot did, most of it just wasn't recorded or generationally civilizational:
You're absolutely right, I know. I guess I wanted to say that the amount of influence in the modern world from these civilizations is rather small (higher in Peru, Bolivia, Mexico maybe). Have you read Guns, germs and steel? It's a fantastic exploration on why Eurasia had a (random) advantage to develop earlier than other places.