Istwa Nou

Speakers of Malayo-Polynesian languages moved out through the Philippines, then across almost all of what is now Indonesia and along the northern coasts of New Guinea, bringing East Asian crops with them, rice above all. In New Guinea they met the peoples already there and took up their plants: taro, breadfruit, yam and sugarcane, several of them from an independent centre of agricultural invention on that island. From about 1500 BCE the Oceanic subgroup began a further scattering eastward that ran for twenty five centuries and put the first farmers, and often the first people of any kind, on islands across Micronesia and Polynesia. Rice stayed behind. The crops that fed the Pacific voyages were the tropical ones picked up by exchange in New Guinea. Polynesian society was built on Papuan plants, much as Egypt was built on cultural foundations that came up the Nile. Borrowing across a linguistic boundary is the thread running through the most distant achievements of the ancient world.

The Bantu expansion is the best known population movement in African history. A second one ran alongside it and is barely mentioned. Between about 3000 and 1000 BCE, peoples speaking Ubangian languages, a subgroup of the North Voltaic branch of Niger-Congo, spread through the lands immediately north of the Bantu regions. They settled most of the vast basin of the Ubangi River, which today means the Central African Republic and the far north of the Democratic Republic of Congo, and by the first millennium BCE their easternmost communities had crossed into western South Sudan. They farmed a mixture of African crops, with yams dominant in the wetter southern parts of the basin and sorghum in the drier north. Two branches of one language family, moving in the same millennia, each carrying agriculture into new country. The Bantu expansion has several hundred studies behind it. The Ubangian expansion, equally consequential for central Africa, has almost none. The imbalance is itself a finding.