Istwa Nou

Growing food supported bigger populations, bigger populations needed more land, and land per head went further under cultivation than under foraging, so farming and herding communities kept pushing outward from wherever they began. When people moved, their speech moved with them. Language never stays still. Word meanings drift, new words get coined or borrowed, grammar shifts, and each generation pronounces the sounds a little differently. Once a single ancestral tongue was being spoken in a dozen separated districts, each district accumulated its own changes, mutual understanding broke down over the centuries, and what had been one language became a family of them. That sequence is the engine behind the linguistic map of the world. Food production drove population growth, growth drove expansion, expansion drove diversification, and the shape of each family tree records who went where and when. Niger-Congo, Nilo-Saharan and Afrasian are demographic history written in sound changes, and they cover ground no potsherd can.

Word histories compared across related languages work as a register of the past, and the great African families make the point. Niger-Congo expansion began in the first four thousand years of the Holocene, carried at first by better returns from collecting wild grain and then by the shift into cultivation. Nilo-Saharan expansion began with an elaborate use of aquatic resources and moved on to herding and cultivation, alongside Cushitic-speaking neighbours doing much the same. The third case is Omotic. In far southwestern Ethiopia, Omotic speakers appear to have invented agriculture on their own around the seventh and sixth millennia BCE, and over the following three thousand years they spread enset farming across the southern Ethiopian highlands and up into the north-central highlands as well. Enset is the false banana, a staple that still feeds millions of Ethiopians and that most of the world has never heard of. Three families, three inventions of farming, three demographic expansions, all African.