The ghosts of West Africa

Bushmen in the Kalahari (Wikicommons, Andy Maano). When recorded history began, in Sumer and Egypt, black Africans were absent from most of Africa, even from most of West Africa. The lands south of the Sahara were largely home to various hunter-gatherers who were small, almost childlike in build, and light reddish-brown in color. 

Most Americans think of native Africans as black and of white Africans as recent intruders; and when they think of Africa's racial history they think of European colonialism and slave trading. But very different types of peoples occupied much of Africa until as recently as a few thousand years ago.

When Jared Diamond penned those words, analysis of ancient DNA was years away. Even when it began, there was a feeling that such analysis would always be impractical in Africa or anywhere else in the tropics. The climate is too warm for that stuff to last thousands upon thousands of years.

Apparently not. DNA has been retrieved from the remains of four individuals at a site in Cameroon, two of them going back 8,000 years and the other two 3,000 years. The main finding? The individuals were most similar to Pygmies, who still exist as isolated groups of hunter-gatherers in the Congo basin. There was no genetic similarity to the Bantu peoples who now predominate throughout central, eastern, and southern Africa (Lipson et al. 2020).

This finding is no surprise. Linguistic evidence has shown that the Bantu are all descended from a group of farming peoples who, some two to three thousand years ago, began to expand eastward and southward from what is now the Cameroon-Nigeria border. 

More intriguing is the discovery of admixture from an extinct West African people. These were hunter-gatherers who shared common ancestry with the Pygmies of central Africa and the Khoisans of southern Africa; however, they had intermixed much more with an archaic hominin that had diverged from ancestral modern humans at about the same time as the Neanderthals:

The West African clade is distinguished by admixture from a deep source that can be modelled as a combination of modern human and archaic ancestry. The modern human component diverges at almost the same point as Central and southern African hunter-gatherers and is tentatively related to the deep source that contributes ancestry to the Mota individual, and the archaic component diverges close to the split between Neanderthals and modern humans (Lipson et al. 2020)

This suggests that the Bantu expansion was the second leg of an earlier expansion of farming peoples who had first replaced the hunter-gatherers of West Africa. This is in line with the thinking of George Murdock, an American anthropologist who argued that black Africans originated with the spread of agriculture from the Niger's headwaters, near the Mali-Guinea border. This region was the cradle of the Sudanic food complex: sorghum, pearl millet, cow pea, and other crops.

Murdock’s scenario is supported by linguistic evidence. Speakers of proto-Niger-Congo broke up around 10,000 years ago, and the oldest group appears to be proto-Mande speakers, whose descendants inhabit the Niger's headwaters (Blench 1984, pp. 128-129; Ehret 1984; Murdock 1959, pp. 44, 64-68). Farming itself seems to have begun later. According to Harris (1976, p. 352), “the problem of dating must be left in abeyance, but it is clear that some form of seed-crop cultivation was underway in the interior at least by the second millennium B.C.”

It looks like a stable population of hunter-gatherers took shape on the Niger’s headwaters around 10,000 years ago. They gradually became proto-agricultural, i.e., more sedentary and better able to manage their food sources. By 4,000 years ago, they had become true farmers and were entering a phase of sustained demographic expansion that would see them colonize the banks of the Niger farther and farther downstream until they reached the rain forest in southern Nigeria. As they adapted to this new environment, they reached a modus vivendi with the Pygmy inhabitants, at first as tenants and then as de facto landowners who took over more and more of the land. Meanwhile, the Pygmies were pushed back farther and farther into the forest until they were no more.

In sum, farming can support a much larger population, and it was this demographic advantage that enabled farming peoples to replace hunter-gatherers, first in West Africa and eventually throughout almost all of sub-Saharan Africa.


Memories of the first West Africans

Those hunter-gatherers are remembered in the traditions of West Africa: 

Pygmies may have been the first inhabitants of Côte d'Ivoire. In their oral tradition, most of the present-day peoples, in particular the Dan-Yacouba, recount that their ancestors, on arriving in the country, found "little red men" whom they pushed back into the forest. Others speak of "little brown men", who had supernatural powers and to whom presents were given to win them over. (Mantongouine 2012)

According to some authors like Allou and Gonnin, the presence of these mysterious beings appears in the oral traditions. They are presented as short beings about 1m 44 to 1m 55 according to J.N. Loucou, with reddish skin, abundant hair, and feet pointing backward. They appear in almost all of the regions of prehistoric Côte d’Ivoire in the sense that almost all of the oral traditions of Côte d’Ivoire’s ethnic groups affirm that they found pygmies in the area before they became established. (Afri 2013; see also Gonnin and Allou 2006; Loucou 1984, p. 18)

Everywhere, but mainly in the countries from which the Pygmies have long disappeared, the Blacks who are considered to be the oldest occupants of the land say that it does not really belong to them and that, when their distant ancestors, coming from the East, established themselves, they found it in the possession of little men with reddish complexions and large heads who were the real natives and who, in exchange for fulfilment of certain agreements, permitted the Negroes who first arrived on a piece of land to enjoy its use and cultivate it. Eventually, those little men disappeared, but the memory of them has persisted. (Delafosse 1922, p. 14)

The Mano of Liberia say that the forested area used to contain only “talking chimpanzees.” These small creatures, called Lam, inhabited the area when the Mano first came. A Lam and his family would live in a hole in the ground (Riddell 1970, p. 27).


Year-round farming, polygyny. and increased stature and robustness

In addition to their means of subsistence, this expanding population of farmers differed from the hunter-gatherers in another way: a much higher rate of polygyny. Farming, especially year-round farming, makes women more self-reliant in feeding themselves and their children, thus cutting the costs, for a man, of having a second wife (van den Berghe 1979, p. 65). The result is a high polygyny rate: 20-50% of all marriages in sub-Saharan farming societies (Bourguignon and Greenbaum 1973, p. 51; Goody 1973; Pebley and Mbugua 1989; Welch and Glick 1981; White 1988).

If some men have more wives, others have to do without. In general, men must compete more keenly with each other for access to women. When such rivalry intensifies in nonhuman species, there is selection for larger, stronger, and more muscular males. This may explain the physical robustness of polygynous farming peoples in sub-Saharan Africa.

This point was studied by Butovskaya et al. (2015) in their study of two East African peoples: the polygynous Datoga and the monogamous Hadza. Datoga men were larger and more robust than Hadza men. They also scored higher on measures of physical aggression, verbal aggression, anger, and hostility. In fact, the two groups differed fundamentally in their attitudes toward aggression:

There is a negative attitude toward aggression among the Hadza but not among the Datoga. In situations of potential aggression, the Hadza prefer to leave. In contrast, aggression is an instrument of social control — both within the family and in outgroup relations — in Datoga society. Datoga men are trained to compete with each other and to act aggressively in particular circumstances.  (Butovskaya et al. 2015).

The two groups also differed at the androgen receptor gene, with the polygynous Datoga more often having an allele that correlated in men with aggressiveness and number of children fathered. Thus, through a process of gene-culture coevolution, a highly polygynous culture has produced a different sort of man, both mentally and physically.

There are other explanations for the diminutive and less robust appearance of African hunter-gatherers. O'Dea (1994) has argued that Pygmies are smaller and less robust because they are less exposed to sunlight in the rain forest and thus less able to synthesize vitamin D and maintain a large and strong skeleton. But how would this theory explain the small, gracile appearance of the Khoisan hunter-gatherers of the Kalahari, who live in an open environment with high solar radiation?


Darker skin

The polygyny rate correlates with darkness of skin, even after you control for latitude (Manning et al. 2004). This is particularly so in sub-Saharan Africa, where highly polygynous farming peoples are noticeable darker than the largely monogamous Pygmy and Khoisan hunter-gatherers. The reason may be a widespread mental association between gender and skin color. Because women are naturally lighter-skinned than men, traditional cultures tend to associate light skin with femininity and dark skin with masculinity (van den Berghe and Frost 1986). There is thus a selective compromise between natural selection for darker skin as a protection against solar radiation and sexual selection for lighter skin as a criterion of femininity (or darker skin as a criterion of masculinity). 

Because unmated women of any kind are scarce in a polygynous society, there is weaker sexual selection for women with lighter skin. This may be why farming peoples are noticeably darker-skinned in sub-Saharan Africa (Frost 2008).


Archaic admixture in West Africa

The ancient DNA study is also consistent with evidence that a partially archaic population used to live in West Africa. One piece of evidence is a skull from a Nigerian site (Iwo Eleru), which is only about 16,300 years old and yet is intermediate in shape between the skulls of modern humans on the one hand and the skulls of Neanderthals and Homo erectus on the other (Harvati et al. 2011; Stojanowski 2014). Furthermore, genomic analysis shows an apparently higher level of Neanderthal ancestry in the Yoruba of Nigeria than in the Luhya of Kenya. This admixture seems to come from a Neanderthal-like population that once lived in West Africa (Hawks 2012).


Conclusion

In the fifteenth century, Europeans discovered a continent whose inhabitants would have looked quite different a millennium earlier. Two tenth-century Arab geographers reported that "in the outer reaches of the land of the Zanj there are cool highlands in which live white Zanj" (Lewis 1990, p. 121, n. 3). The Zanj are the dark-skinned peoples of east Africa and the “white Zanj” were probably the Khoisan hunter-gatherers who once inhabited the inland plateau of southern Africa.

If we could rewind history, we would see true black Africans retreating progressively to West Africa and then to the area of the Niger’s headwaters. This leads us to a strange conclusion. When recorded history began, in Sumer and Egypt, black Africans were absent from most of Africa, even from most of West Africa. Perhaps they didn’t yet exist anywhere. The lands south of the Sahara were largely home to various hunter-gatherers who were small, almost childlike in build, and light reddish-brown in color. 


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