two or more states. In contrast to most of Central, Southern and Southeast Africa, West Africa is not populated by Bantu-speaking peoples. Prehistory West African populations were considerably mobile and interacted with one another throughout the population history of West Africa. Acheulean tool-using archaic humans may have dwelled throughout West Africa since at least between 780,000 BP and 126,000 BP (Middle Pleistocene). During the Pleistocene, Middle Stone Age peoples (e.g., Iwo Eleru people, possibly Aterians), who dwelled throughout West Africa between MIS 4 and MIS 2, were gradually replaced by incoming Late Stone Age peoples, who migrated into West Africa as an increase in humid conditions resulted in the subsequent expansion of the West African forest. West African hunter-gatherers occupied western Central Africa (e.g., Shum Laka) earlier than 32,000 BP, dwelled throughout coastal West Africa by 12,000 BP, and migrated northward between 12,000 BP and 8000 BP as far as Mali, Burkina Faso, and Mauritania. During the Holocene, Niger-Congo speakers independently created pottery in Ounjougou, Mali – the earliest pottery in Africa – by at least 9400 BCE, and along with their pottery, as well as wielding bows and arrows, migrated into the Central Sahara, which became their primary region of residence by 10,000 BP. The emergence and expansion of ceramics in the Sahara may be linked with the origin of Round Head and Kel Essuf rock art, which occupy rockshelters in the same regions (e.g., Djado, Acacus, Tadrart). Hunters in the Central Sahara farmed, stored, and cooked undomesticated central Saharan flora, domesticated antelope, and domesticated and shepherded Barbary sheep. After the Kel Essuf Period and Round Head Period of the Central Sahara, the Pastoral Period followed. Some of the hunter-gatherers who created the Round Head rock art may have adopted pastoral culture, and others may have not. As a result of increasing aridification of the Green Sahara, Central Saharan hunter-gatherers and cattle herders may have used seasonal waterways as the migratory route taken to the Niger River and Chad Basin of West Africa. Migration of Saharan peoples south of the Sahelian region resulted in seasonal interaction with and gradual absorption of West African hunter-gatherers, who primarily dwelt in the savannas and forests of West Africa. After having persisted as late as 1000 BP, or some period of time after 1500 CE, remaining West African hunter-gatherers, many of whom dwelt in the forest-savanna region, were ultimately acculturated and admixed into