The Diversity of Indigenous Africans
Professor S. 0. Y. Keita
Department of Biological Anthropology
The living peoples of the African continent are diverse in facial characteristics, stature, skin color, hair form, genetics, and other characteristics. No one set of characteristics is more African than another. Variability is also found in "sub-Saharan" Africa, to which the word "Africa" is sometimes erroneously restricted. There is a problem with definitions. Sometimes Africa is defined using cultural factors, like language, that exclude developments that clearly arose in Africa. For example, sometimes even the Horn of Africa (Somalia, Ethiopia, Eritrea) is excluded because of geography and language and the fact that some of its peoples have narrow noses and faces. However, the Horn is at the same latitude as Nigeria, and its languages are African. The latitude of 15 degree passes through Timbuktu, surely in "sub-Saharan Africa," as well as Khartoum in Sudan; both are north of the Horn. Another false idea is that supra-Saharan and Saharan Africa were peopled after the emergence of "Europeans" or Near Easterners by populations coming from outside Africa. Hence, the ancient Egyptians in some writings have been de-Africanized. These ideas, which limit the definition of Africa and Africans, are rooted in racism and earlier, erroneous "scientific" approaches. Classical European writers ("eyewitnesses") are not very helpful either, since they were not working within modern science. Ancient Greeks made a distinction between Egyptians and "Ethiopians," but such a distinction does not mean that the ancient Egyptians were not Africans. Also, it is not clear whether the distinction was actually sometimes more cultural than biological. Curiously, some Greeks reported that Egypt was an Ethiopian colony.
There is a stereotyped image in the minds of many people about what a "real" African looks like, or what characteristics can be "authentically" African. This stereotype also affects scientists, as noted with candor by Professor Jean Hiernaux (1975:54).
Stereotyped concepts of African human biology seem to persist because of a failure to integrate the facts of paleontology, genetics, and ecology into an interpretive framework based on evolutionary principles. This failure has led some scholars erroneously to explain that diversity in Africa is mainly the result of "true Africans" intermarrying with invaders or colonists from Europe and Asia. Hence, the eye fold, yellow skin, and hair form of most Khoisan speakers were once explained as the result of a very ancient mixing of "Mongoloids" with "true Africans." The narrow noses and faces of many Tutsi were seen as the result of "Caucasian," and ultimately European, admixture. What is wrong with these explanations, given that "intermarriage" does take place, producing people with "variable" features? The answer is straightforward, although multifaceted. First, the explanations are mainly the result, erroneous theories that postulated that humans had evolved into distinct non-overlapping types at some point in the past. This required explaining all variation as a product of the blending of these types. This perspective largely predates modern understanding, yet it persists to some degree! Secondly, there are no adequate data supporting the massive invasions of Africa required by these explanations, especially those that imply that some groups resident in Africa are not African in origin.
The diversity of Africans, which includes ancient Egyptian; and Berber speakers, is real and largely indigenous. An evolutionary perspective helps us understand why. Modem Homo sapiens have lived in Africa longer than anywhere else, according to most scholars. This length of time means that more random genetic mutations, the ultimate source of genetic variation, have accumulated in Africa. Furthermore, Africa is climatically and ecologically diverse. This favors diversification by Darwinian selection. The continent is large, which allows great movements and fissioning of populations. This promotes random genetic variation, since small portions of larger populations rarely accurately represent the range of genetic variation in a larger group, whether it is ancestral or exists at the same time.
Molecular data suggest that the early modern human population began to divide between 150,000 to 115,000 years ago. This fissioning would have taken place in Africa. Modern human fossils dated to about 90,000 years ago are found outside Africa, but the next genetic fissioning is believed to have occurred after this, perhaps about 70,000 years ago (Bowcock et al. 1991). Modern human remains in Asia, including Australia, are dated after this period, and in Europe, to around 35,000 years ago. Why are these data important? Because they indicate that the background genetic variation of Europeans, Oceanians, and Asians originated in Africa and precedes in time the presence of modern humans in these areas. Europeans and Asian-Australians did develop more unique genetic profiles over time, but had a common background before their average "uniqueness" emerged. This background is African in a bio-historical sense. Therefore, it should not be surprising that some Africans share similarities with non-Africans.
The alternative to this explanation would be that a population of genetically uniform individuals left Africa before or between 100,000 and 90,000 years ago, evolved into ancestral Europeans, Oceanians, and Asians, and then returned at some point to Africa. This would then account for certain resident Africans having genetic characteristics only found in Africa, and others being similar to non-Africans. The various kinds of data do not support this scenario. No part of Africa was initially populated from Eurasia-Australia in the time frames given, nor to any great degree in the last 15,000 years, in the sense of different populations replacing each other. This does not mean that the relatively recent historic movements of Europeans and Near Easterners did not probably have some impact on northern African gene pools. However, it may be difficult to determine which genetic variants are not indigenous to northern Africa.
It is important to note that a small amount (one to five percent) of sustained migration, generation after generation, into a population can alter its genetic character in a few thousand years, assuming that the migrants freely intermarry. This is not the same as a new population coming in and displacing, exterminating, or reproducing in greater numbers than the locals. However, both can have the same genetic results. Historical genetic analyses and hypotheses are made more difficult when newcomers may be only slightly different genetically.
"Hamitic hypothesis" is the name given to the migration theory developed by Seligman (Sanders 1969). This theory postulated that "Hamites" migrated to Africa from the Near East bringing new languages, superior genes, and culture and influencing the indigenous people. Hamites were seen as lost Europeans. Hamites allegedly peopled Northern Africa and influenced other regions. Narrow noses and faces, lighter skin, straighter hair, certain lifestyles, and political systems were attributed to Hamites, such that wherever these were found, "Hamitic blood" was alleged to be the source. This is all now known to be untrue. The so-called Hamitic languages are part of a family called Afroasiatic or Afrasian (formerly Hamito-Semitic), which originated in Africa. Only one branch, called Semitic, is spoken outside of Africa.
Admixture with non-Africans probably does not explain the bulk of the variation from Algeria to South Africa, although northern Africa was more affected in this regard. At the DNA level great African continent-wide diversity preceded the minor European and Near Eastern migrations of later Holocene times. There may have been some migration during the Neolithic Period, although Neolithic Northern African sites do not, in the main, look like the work of European or Near Eastern settler colonists. Even "new" "non-African" genes would be subject to the human and physical environment of Africa and hence would be reworked, thereby becoming a part of African biohistory, just as recent tropical African genes have been processed in Greece, Sicily and Portugal. In any case, it is important to reiterate that Africa equals diversity. Evolutionary theory predicts and extrapolations from molecular analyses and skeletal remains all indicate an early and ongoing diversity in the indigenous populations of Africa. The implication of this is that terms like "Negro," "Caucasian," "Hamite," etc., are misleading and non-scientific as applied to Africa.