After having done some preliminary reading on the Bantu Expansion lately, it has come to my attention that the Bantus did not begin to make their first incursions into the Zambezi River Valley until the Common Era. This leaves a large portion of Africa populated by the hunter-gatherer Khoisan peoples who were relatively few in numbers. It has always seemed like something of a quirk to me that Madagascar was settled by people from Borneo (and a very specific area of a specific river in Borneo, nonetheless), who in turn, after having made such an incredible voyage across the Indian Ocean were content to sit on their admittedly massive island and wait for the Bantu to arrive.
Getting Dravidians to Madagascar by say, 200 or even 500 BCE seems easy enough to me, but can we posit the settlement of somewhere on the continent, like Mozambique? Potentially Zimbabwe/South Africa down the road? I know that disease was a significant factor in European settlement of Africa, but was it for the Indians that settled there? If so, can this be averted? For example, I have read that the tsetse fly didn’t begin to expand into other parts of Africa until the middle of the 19th century, so that might not be a problem for them and their livestock.
Also, how does South Indian culture develop in Africa? At such an early date, will the Dravidians of Africa maintain strong ties with their homelands or, like the Malagasy peoples, will they lose touch with them and develop a new culture, or a series of new cultures, perhaps by way of intermarriage with the Khoisan/Bantu?