Credited to Mauritania. Dhar Tichitt was long presented as a case of gradual local domestication of wild millet. Augustin Holl notes that fully domesticated millet of the early 2nd millennium BCE at Dhar Walata, and of similar date at Birimi in Ghana, makes the gradual local model unlikely, so the place of first domestication is not settled.
How it began
The sandstone escarpment of Dhar Tichitt in south-central Mauritania was settled by Neolithic farming and herding communities from about 4000 to 2300 years before present, roughly 2000 to 300 BCE. Augustin Holl writes that these herders succeeded in domesticating bulrush (pearl) millet. Domesticated millet dated to the start of the 2nd millennium BCE has been found at Dhar Tichitt and at Oued Chebbi in neighboring Dhar Walata.
Before it existed
The people who settled the cliffs had moved south as the Sahara dried, toward more humid lower latitudes. They lived by herding livestock and hunting. Holl writes that they took advantage of the peculiarities of the local geology and environment, which gave them a foothold in a landscape that was turning to desert.
How it works
The communities grew millet for grain alongside herding and hunting, and Holl describes seasonal movement between locations as the climate shifted. Families lived in compounds enclosed by drystone walls. Wikipedia counts about 500 such settlements along the escarpment, arranged in a hierarchy of villages and hamlets that points to an organized society.
How it spread
Holl describes a second wave of evidence for domesticated millet around the turn of the 1st millennium BCE at Oursi in Burkina Faso and Gajiganna in Nigeria. The crop then spread widely and reached the rainforest and East Africa during the 1st millennium BCE. The Tichitt tradition itself extended along the cliffs to Dhar Walata and Dhar Nema.
What lasted
An intense arid period led to social change and the abandonment of the area by about 300 BCE. Holl suggests the communities evolved toward larger polities as they coped with the climate, and both sources link the end of Tichitt to the later rise of the Ghana Empire. Pearl millet remained a staple grain of the Sahel.
