Human Biological Diversity in Central Africa

Abstract

The object of this paper is to summarise the results of an anthropological biological survey made in Ig5o-6 on the breeding populations of an area including Rwanda, Burundi, and part of the Kivu province of the ex-Belgian Congo (Hiernaux i956; ig60; i963; i964; i965a). The author was based at the Astrida (now Butare) centre of the Institut pour la Recherche Scientifique en Afrique centrale (IRSAC), where he derived benefit from the presence of several ethnologists, a linguist, a demographer, and an economist. The paper will start with a few general remarks on the prospects of survey work in physical anthropology and on its strategy. On one point, taxonomy, it will extend beyond the geographical frame considered, and include some preliminary and partial results of research now in progress. The object of study of physical anthropology is the biological diversity of Man. This can be approached in various ways. Mathematicians working on models, atid biologists experimenting on mice have made contributions of prime importance for the theoretical understanding of human diversity. When all the published quantified information on the biological characters of ethnic groups living in Africa south of the Sahara is considered, discarding only those samples which are too small or are not representative, about half of the area is a terra incognita from this point of view. Data exist on 460 groups, but there is no one variable common to them all (Hiernaux ms.). We evidently need more data on more populations if we are to solve those anthropological problems which cover a wide African area, such as the taxonomy of Man in Africa, or the associations between environmental and biological variables. The Human Adaptability Committee of the International Biological Programme has been wise in recommending more extensive surveys on biological characters everywhere in the world, like the one in central Africa dealt with here. While the lack of data is still so great that any survey will collect something of interest, some areas are, however, more interesting than others. These are areas in which there are wide variations of both environment and gene pools. There is a fair probability that the investigator starting a survey in such a part of the world will find situations approximating a latin square in design, or at least comprising several cells of it. The simplest latin square, one with four cells, would consist of two genetically different populations living in two different biotopes. Such a situation would allow one to analyse the overall diversity into that part due to genetical causes and that part due to the influence of the environment on the phenotype. The Rwanda area is favourable in this respect: its inhabitants display an extreme intergroup diversity, and ecologically it is a contact area where the equatorial forest and the eastern savannah meet. It also receives influences from the north along the Nile and from the south along the Great Lakes rift.