Recognizing population displacements and replacements in prehistory: A view from North Africa

Recognizing population displacements and replacements in prehistory: A view from North Africa

C.M. Stojanowski. Center for Bioarchaeological Research, School of Human Evolution and Social Change, Arizona State University.

Bioanthropologists use skeletal data to reconstruct the historical global distribution of humans. One of the more critical and contentious issues is the inference that a complete population replacement has occurred which has importance for our understanding of human biological variation as well as issues of cultural patrimony. Despite the ubiquity of such analyses, problems exist with current methods because the degree of phenotypic change through time is dependent on demographic parameters, processes of selection, and changes in subsistence orientation which reflect the malleability of cranial form. How different do two populations need to be for continuity to be rejected? In this paper the population history of northwestern African and central Saharan populations is discussed from the Late Pleistocene through Early Holocene. Craniometric data are used from nine chrono-spatial samples to address the relationship between temporally sequential populations in North Africa where long term changes in aridity prevented human occupation for several distinct intervals. R matrix analysis resolves several perceived population discontinuities based on analyses of lithic assemblages. Population structure indicates a replacement of indigenous Aterian (early modern human) populations by makers of the Iberomaurusian industry ca 18kybp. Population continuity is suggested between the Iberomaurusian and Capsian horizons, and the analysis suggests the expansion of Late Pleistocene populations from the Maghreb into the Sahara as climate improved during the Holocene. Finally, a second population replacement is inferred during the Middle Holocene in the central Sahara coincident with the advent of pastoralism.

The result of a little blog raiding at Dienekes. There’s a pdf from the AAPA full of interesting abstracts here, which I’m working my way through. This one caught my eye-being about North Africa. I t mentions the replacement of the Aterians by the IM industry, and the central Saharan population replacement in the Holocene. Unfortunately it doesn’t say who replaced who; the incoming neolithic mediterannoids replacing the Mechtoid Saharans possibly, although it could be another group, as the groups aren’t specified, but being familiar with the desciptions of Neolithic Saharans by various authors that would be my guess.

It also notes the North African (Mechtoid again) expansion into the Sahara which would have been about 12,000 years ago when the Sahara went through a wet phase. A DNA study on the bones of the Mechtoid population from Taforalt have shown them to be mainly of Eurasian mitochondrial types, and they are very similar to to bones  found as far South as Mali. However, it’s quite likely a good proportion of their Y chromosomes were East African and North East African in origin, as some of the populations show up as intermediate to Eurasian and sub Saharan groups of the same era (although not Taforalt).

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