If you are going to integrate Central Asia into your history, you can absolutely integrate sub-Saharan Africa into your history. You just can't talk about the Indian Ocean unless you talk about eastern Africa. And you can't talk about Mediterranean history unless you know what's going on in West Africa. You can't talk about the Red Sea and the Middle East unless you're talking about Ethiopia actually, for the Middle East, you need West Africa and East Africa too. If you're doing world history, you need to connect up all these places.
people who do world history usually begin with the origins of agriculture. There are at least seven or eight maybe eleven to thirteen world regions which independently invented agriculture. None in Europe, by the way. One, of course, is in the Middle East, and many people still believe that this was the first, from which all the others developed. The idea of diffusion from the Middle East still lingers.
That idea really can't be sustained.
You have, for instance, one independent invention of agriculture in East Asia, maybe two. You have it more widely accepted now that there's an independent invention of agriculture in the interior of New Guinea. People argue about what to make of the Indian materials, but certainly India saw one of the three separate domestications of cattle; there are enough uniquely Indian crops that we might end up with India as another center of independent agricultural innovation. There are different ideas about the Americas, but I think we have two for sure: Mesoamerica and the Andes. There may also be a separate lowland tropical South American development. It also seems that there might be a few things domesticated in the southeastern United States even before there was Mesoamerican stimulus or diffusion. So that makes four.
Here's the point: agriculture was invented in Africa in at least three centers, and maybe even four. In Africa, you find the earliest domestication of cattle. The location, the pottery and other materials we've found makes it likely that happened among the Nilo-Saharan peoples, the sites are in southern Egypt. There is an exceptionally strong correlation between archaeology and language on this issue.