Ancient teeth and modern human origins

[Ayinde]

Ancient teeth and modern human origins: An expanded comparison of
African Plio-Pleistocene and recent world dental samples

Journal of Human Evolution
Article in Press,

Abstract

Previous research by the first author revealed that, relative to other modern peoples, sub-Saharan Africans exhibit the highest frequencies of ancestral (or plesiomorphic) dental traits and, thus, appear to be least derived dentally from an ancestral hominin state.

This determination, in conjunction with various other lines of dental morphological evidence, was interpreted to be supportive of an African origin for modern humans. The present investigation expands upon this work by using: 1) direct observations of fossil hominin teeth, rather than data gleaned from published sources, 2) a single morphological scoring system (the Arizona State University Dental Anthropology System) with consistent trait breakpoints, and 3) data from larger and more varied modern human comparative samples. As before, a multivariate distance statistic, the mean measure of divergence, was used to assess diachronic phenetic affinities among the Plio-Pleistocene hominins and modern humans. The present study also employed principal components analysis on dental trait frequencies across samples. Both methods yielded similar results, which support the previous findings; that is, of all modern human samples, sub-Saharan Africans again exhibit the closest phenetic similarity to various African Plio-Pleistocene hominins––through their shared prevalence of morphologically complex crown and root traits.

The fact that sub-Saharan Africans express these apparently plesiomorphic characters, along with additional information on their affinity to other modern populations, evident intra-population heterogeneity, and a world-wide dental cline emanating from the sub-continent, provides further evidence that is consistent with an African origin model.

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Joel D. IrishCorresponding Author Contact Information, E-mail The
Corresponding Author, a and Debbie Guatelli-SteinbergE-mail The
Corresponding Author, b

a Department of Anthropology, University of Alaska Fairbanks,
Fairbanks, AK 99775-7720, USA
b Department of Anthropology and Department of Evolution, Ecology and
Organismal Biology, The Ohio State University, Newark, OH 43055, USA

Received 4 September 2002; accepted 4 June 2003. ; Available online
10 September 2003.


Author Keywords: Dental morphology; Phenetic affinity; Ancestral and derived traits; Australopithecus; Paranthropus; Early and modern Homo; Human origins; Africa