Prehistory in blood and bone: An essay on the reconstruction of the past from genetics and morphology

Abstract

Recent advances in genetic studies of modern humans have proved to be invaluable in tracking the relationships of living human populations through time. This has led to the impression in some quarters that osteological study of fossils has become an outmoded field and has been superceded by genetics. Certainly the use of non-adaptive DNA sequences to record the accumulation of random mutations over time has resulted in an objective method of measuring genetic distances between populations, but there is still much that can be learnt from the study of archaeological bones. Carbon isotope variation reveals prehistoric diets, while samples from cemetery sites provide crucial demographic information, and close study of the individual skeletons can disclose features of growth, life habit and palaeopathology. Ancient DNA is a relatively new field that has yet to make its mark in South African science. The apparent disjunction between the archaeological appearance of modern morphological patterns in KhoiSan populations and the great antiquity of these same populations according to serogenetic data implies that our understanding of the nuclear genome and how it codes for morphology remains far from complete. Until the morphological controls of nuclear genomics are better understood, morphometrics of archaeological specimens will remain the best method of reconstructing prehistoric population patterns from excavated samples.