Population history of West Africa

The population history of West Africa is composed of West African populations that were considerably mobile and interacted with one another throughout the 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. During the Pleistocene, Middle Stone Age peoples, 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 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 independently invented 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. Hunters in the Central Sahara farmed, stored, and cooked undomesticated central Saharan flora, underwent domestication of 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. In 2000 BCE, "Thiaroye Woman", also known as the "Venus of Thiaroye," may have been the earliest statuette created in Sub-Saharan West Africa; it may have particularly been a fertility statuette, created in the region of Senegambia, and may be associated with the emergence of complexly organized pastoral societies in West Africa between 4000 BCE and 1000 BCE. Though possibly developed as early as 5000 BCE, Nsibidi may have also developed in 2000 BCE, as evidenced by depictions of the West African script on Ikom monoliths at Ikom, in Nigeria. 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. In West Africa, which may have been a major regional cradle in Africa for the domestication of crops and animals, Niger-Congo speakers domesticated the helmeted guineafowl between 5500 BP and 1300 BP; domestication of field crops occurred throughout various locations in West Africa, such as yams in the Niger River basin between eastern Ghana and western Nigeria, rice in the Inner Niger Delta region of Mali, pearl millet in northern Mali and Mauritania, and cowpeas in northern Ghana. 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 the larger groups of West African agriculturalists, akin to the migratory Bantu-speaking agriculturalists and their encounters with Central African hunter-gatherers.
With the emergence of the West African Iron Age, iron metallurgy developed in ancient West African civilizations, such as Tichitt culture and Nok culture. Following the flourishing of Iron Age West African civilizations, periods of mass enslavement, such as the Trans-Atlantic slave trade, contributed to the depopulation of West Africa. At least 6,284,092 West Africans are estimated to have been enslaved and taken captive during the Trans-Atlantic slave trade; along with Africans enslaved and taken captive in other embarking regions of Africa, such as Central Africa and Southern Africa, as well as between at least 12% and 13% of enslaved Africans taken captive estimated to have died during the Middle Passage, the overall number of Africans enslaved and taken captive during the Trans-Atlantic slave trade is estimated to have been at least 12,521,335. During the modern period, the population of West Africa is estimated to have increased from 69,564,958 in 1950 CE to 413,340,896 in 2021 CE.

Climate

Early Stone Age

Middle Stone Age

In the Falémé River Valley zone, with the exception of stadial phases and interstadial phases, there has been a fairly steady state of humidity and temperature throughout a span of 120,000 years. Additionally, for at least the previous 100,000 years, the presence of flora has remained quite consistent. Consequently, this region has remained habitable for human populations, from the Early Stone Age, through the Middle Stone Age, to the Later Stone Age. Furthermore, for the previous 100,000 years, compared to the climate of East Africa, the Pleistocene climate in West Africa has been more steady and humid.
In the Jos Plateau zone, the Pleistocene climate has fluctuated mostly during stadial phases and interstadial phases, throughout the previous 120,000 years; specifically, stable climate occurred between MIS 4 and MIS 2, and climate fluctuations occurred during the periods and sub-periods of MIS 1 and MIS 5. Consequently, the human habitation in Jos Plateau, which is only composed of Middle Stone Age sites, has been distinct in terms of culture and environment in comparison to the Falémé River Valley.
In the Atakora mountainous zone, the Pleistocene climate has supported continuity in human habitation, from the Early Stone Age, through the Middle Stone Age, to the Later Stone Age, which spanned the previous 120,000 years.

Later Stone Age

In the Falémé River Valley zone, with the exception of stadial phases and interstadial phases, there has been a fairly steady state of humidity and temperature throughout a span of 120,000 years. Additionally, for at least the previous 100,000 years, the presence of flora has remained quite consistent. Consequently, this region has remained habitable for human populations, from the Early Stone Age, through the Middle Stone Age, to the Later Stone Age. Furthermore, for the previous 100,000 years, compared to the climate of East Africa, the Pleistocene climate in West Africa has been more steady and humid.
In the Atakora mountainous zone, the Pleistocene climate has supported continuity in human habitation, from the Early Stone Age, through the Middle Stone Age, to the Later Stone Age, which spanned the previous 120,000 years.
In 15,000 BP, the West African monsoon transformed the landscape of Africa and began the Green Sahara period; greater rainfall during the summer season resulted in the growth of humid conditions and the savanna in North Africa. Between 5500 BP and 4000 BP, the Green Sahara period ended.

Pastoral Neolithic

By 4500 BP, sources of water in the Sahara had dried, and subsequently, drought occurred, which resulted in a decrease in the presence of humidity in the region. Concurrent with the decrease of humidity in the Sahara, between 3500 BP and 2500 BP, there was an increase of humidity in the Sahel.

Iron Age

During the 1st millennium cal BCE, between the Later Stone Age and Early Iron Age, the environment was conducive for the growth of pearl millet in the Lake Chad Basin.

Material culture and archaeological data

Early Stone Age

tool-using archaic humans may have dwelled throughout West Africa since at least between 780,000 BP and 126,000 BP.

Middle Stone Age

Middle Stone Age West Africans likely dwelled continuously in West Africa between MIS 4 and MIS 2 and likely were not present in West Africa before MIS 5. Amid MIS 5, Middle Stone Age West Africans may have migrated across the West Sudanian savanna and continued to reside in the region. In the Late Pleistocene, Middle Stone Age West Africans began to dwell along parts of the forest and coastal region of West Africa. More specifically, by at least 61,000 BP, Middle Stone Age West Africans may have begun to migrate south of the West Sudanian savanna, and, by at least 25,000 BP, may have begun to dwell near the coast of West Africa. Amid aridification in MIS 5 and regional change of climate in MIS 4, in the Sahara and the Sahel, Aterians may have migrated southward into West Africa.

Later Stone Age

Earlier than 32,000 BP, or by 30,000 BP, Late Stone Age West African hunter-gatherers were dwelling in the forests of western Central Africa. An excessively dry Ogolian period occurred, spanning from 20,000 BP to 12,000 BP. By 15,000 BP, the number of settlements made by Middle Stone Age West Africans decreased as there was an increase in humid conditions, expansion of the West African forest, and increase in the number of settlements made by Late Stone Age West African hunter-gatherers. Macrolith-using late Middle Stone Age peoples, who dwelled in Central Africa, to western Central Africa, to West Africa, were displaced by microlith-using Late Stone Age Africans as they migrated from Central Africa, to western Central Africa, into West Africa. Between 16,000 BP and 12,000 BP, Late Stone Age West Africans began dwelling in the eastern and central forested regions of West Africa. By 11,000 BP, the late settlement made by Middle Stone Age West Africans and earliest settlement made by Late Stone Age West African hunter-gatherers emerged in the westernmost region of West Africa. Middle Stone Age West Africans and Late Stone Age West African hunter-gatherers likely did not become admixed with one another and were culturally and ecologically distinct from one another.
In the 10th millennium BCE, Niger-Congo speakers developed pyrotechnology and employed subsistence strategy at Ounjougou, Mali. Prior to 9400 BCE, Niger-Congo speakers independently created and used matured ceramic technology to contain and cook grains ; ethnographically and historically, West African women have been the creators of pottery in most West African ceramic traditions and their production of ceramics is closely associated with creativity and fertility. Amid the tenth millennium BCE, microlith-using West Africans migrated into and dwelt in Ounjougou alongside earlier residing West Africans in Ounjougou. Among two existing cultural areas, earlier residing West Africans in Ounjougou were of a cultural area encompassing the Sahara region of Africa and microlith-using West Africans were of a cultural area encompassing the forest region of West Africa.
Following the Ogolian period, between the late 10th millennium BCE and the early 9th millennium BCE, the creators of the Ounjougou pottery – the earliest pottery in Africa – migrated, along with their pottery, from Ounjougou, Mali into the Central Sahara. The emergence and expansion of ceramics in the Sahara may be linked with the origin of both the Round Head and Kel Essuf rock art, which occupy rockshelters in the same regions as well as have a common resemblance. Whether or not Ounjougou ceramic culture spread as far as Bir Kiseiba, Egypt, which had pottery that resembled Ounjougou pottery, had implements used for grinding like at Ounjougou, and was followed by subsequent ceramic cultures, remains to be determined. Between 8200 BCE and 6400 BCE, Central Saharan hunter-gatherers of Libya gathered a diverse selection of flora and used ceramic pots to process and cook the flora. By 10,000 BP, the primary region of residence for Niger-Congo speakers, who wielded bows and arrows, may have been the southern region of the Central Sahara. Amid an early period of the Holocene, semi-settled Epipaleolithic and Mesolithic hunters, who created a refined material culture as early as 10,000 BP, also created the engraved Kel Essuf and painted Round Head rock art styles located in the region of Libya, in the region of Algeria, in the region of Nigeria, and the region of Niger. Amid the early Sahara, Round Head rock artists, who had a sophisticated culture and engaged in the activity of hunting and gathering, also developed pottery, used vegetation, and managed animals. The cultural importance of shepherded Barbary sheep is shown via their presence in Round Head rock art throughout the Central Sahara. Barbary sheep were corralled in stone enclosures near Uan Afuda cave. From up to 9500 BP, this continued until the beginning of the Pastoral Neolithic in the Sahara. Between 7500 BCE and 3500 BCE, amid the Green Sahara, undomesticated central Saharan flora were farmed, stored, and cooked, and domesticated animals were milked and managed, by hunter-gatherers near the Takarkori rockshelter, which is representative of the broader Sahara; this continued until the beginning of the Pastoral Neolithic in the Sahara.
File:Fondazione Passaré V31 474.jpg|thumb|200px|Round Head figure wearing a Barbary sheep-styled mask