Man made the African savannas (ancient climate change)

[Al B. Sure!]

Another stream of migration, moving east by 3000 years ago (1000 B.C.), was creating a major new population center near the Great Lakes of East Africa, where a rich environment supported a dense population. Movements by small groups to the southeast from the Great Lakes region were more rapid, with initial settlements widely dispersed near the coast and near rivers, due to comparatively harsh farming conditions in areas further from water. Pioneering groups had reached modern KwaZulu-Natal in South Africa by 300 A.D. along the coast, and the modern Limpopo Province (formerly Northern Transvaal) by 500 A.D.[24][25][26]

The Zulu, obviously were Bantu. They grew sorghum, as well.

Diamond is wrong about crop diffusion. Maize was grown from Peru to North America. Sorghum and millet were grown in Northern China, India, and through much of Africa. Crops got around North-South as much as East-West.

[Dinner]

So far you haven't pointed out one thing he was wrong about since he listed all of those crops and where they diffused in ancient times. Also there are several different types of millet out there each with different places of origin. Oh, and only a ****** wouldn't know Zulus were bantu.