Assessing endocranial variations in great apes and humans using 3D data from virtual endocasts
Article first published online: 1 MAR 2011
Copyright © 2011 Wiley-Liss, Inc.
American Journal of Physical Anthropology
Volume 145, Issue 2, pages 231–246, June 2011
How to Cite
Bienvenu, T., Guy, F., Coudyzer, W., Gilissen, E., Roualdès, G., Vignaud, P. and Brunet, M. (2011), Assessing endocranial variations in great apes and humans using 3D data from virtual endocasts. Am. J. Phys. Anthropol., 145: 231–246. doi: 10.1002/ajpa.21488
- Issue published online: 17 MAY 2011
- Article first published online: 1 MAR 2011
- Manuscript Accepted: 13 DEC 2010
- Manuscript Received: 15 JUL 2010
- Agence Nationale de la Recherche. Grant Number: ANR-09-BLAN-0238
- Allocation de Recherche of the French Ministère de l'Enseignement Supérieur et de la Recherche
- comparative anatomy;
Modern humans are characterized by their large, complex, and specialized brain. Human brain evolution can be addressed through direct evidence provided by fossil hominid endocasts (i.e. paleoneurology), or through indirect evidence of extant species comparative neurology. Here we use the second approach, providing an extant comparative framework for hominid paleoneurological studies. We explore endocranial size and shape differences among great apes and humans, as well as between sexes. We virtually extracted 72 endocasts, sampling all extant great ape species and modern humans, and digitized 37 landmarks on each for 3D generalized Procrustes analysis. All species can be differentiated by their endocranial shape. Among great apes, endocranial shapes vary from short (orangutans) to long (gorillas), perhaps in relation to different facial orientations. Endocranial shape differences among African apes are partly allometric. Major endocranial traits distinguishing humans from great apes are endocranial globularity, reflecting neurological reorganization, and features linked to structural responses to posture and bipedal locomotion. Human endocasts are also characterized by posterior location of foramina rotunda relative to optic canals, which could be correlated to lesser subnasal prognathism compared to living great apes. Species with larger brains (gorillas and humans) display greater sexual dimorphism in endocranial size, while sexual dimorphism in endocranial shape is restricted to gorillas, differences between males and females being at least partly due to allometry. Our study of endocranial variations in extant great apes and humans provides a new comparative dataset for studies of fossil hominid endocasts. Am J Phys Anthropol, 2011. © 2011 Wiley-Liss, Inc.