MORPHOLOGICAL INTEGRATION IN THE HOMININ DENTITION: EVOLUTIONARY, DEVELOPMENTAL, AND FUNCTIONAL FACTORS
Article first published online: 5 JAN 2012
© 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Volume 66, Issue 4, pages 1024–1043, April 2012
How to Cite
Gómez-Robles, A. and Polly, P. D. (2012), MORPHOLOGICAL INTEGRATION IN THE HOMININ DENTITION: EVOLUTIONARY, DEVELOPMENTAL, AND FUNCTIONAL FACTORS. Evolution, 66: 1024–1043. doi: 10.1111/j.1558-5646.2011.01508.x
- Issue published online: 6 APR 2012
- Article first published online: 5 JAN 2012
- Accepted manuscript online: 15 NOV 2011 12:50AM EST
- Received June 29, 2011 , Accepted October 19, 2011
- Developmental constraints;
- geometric morphometrics;
- serial homology;
- stabilizing selection
As the most common and best preserved remains in the fossil record, teeth are central to our understanding of evolution. However, many evolutionary analyses based on dental traits overlook the constraints that limit dental evolution. These constraints are diverse, ranging from developmental interactions between the individual elements of a homologous series (the whole dentition) to functional constraints related to occlusion. This study evaluates morphological integration in the hominin dentition and its effect on dental evolution in an extensive sample of Plio- and Pleistocene hominin teeth using geometric morphometrics and phylogenetic comparative methods. Results reveal that premolars and molars display significant levels of covariation; that integration is stronger in the mandibular dentition than in the maxillary dentition; and that antagonist teeth, especially first molars, are strongly integrated. Results also show an association of morphological integration and evolution. Stasis is observed in elements with strong functional and/or developmental interactions, namely in first molars. Alternatively, directional evolution (and weaker integration) occurs in the elements with marginal roles in occlusion and mastication, probably in response to other direct or indirect selective pressures. This study points to the need to reevaluate hypotheses about hominin evolution based on dental characters, given the complex scenario in which teeth evolve.