Biomechanical implications of intraspecific shape variation in chimpanzee crania: moving toward an integration of geometric morphometrics and finite element analysis.


Journal Article

In a broad range of evolutionary studies, an understanding of intraspecific variation is needed in order to contextualize and interpret the meaning of variation between species. However, mechanical analyses of primate crania using experimental or modeling methods typically encounter logistical constraints that force them to rely on data gathered from only one or a few individuals. This results in a lack of knowledge concerning the mechanical significance of intraspecific shape variation that limits our ability to infer the significance of interspecific differences. This study uses geometric morphometric methods (GM) and finite element analysis (FEA) to examine the biomechanical implications of shape variation in chimpanzee crania, thereby providing a comparative context in which to interpret shape-related mechanical variation between hominin species. Six finite element models (FEMs) of chimpanzee crania were constructed from CT scans following shape-space Principal Component Analysis (PCA) of a matrix of 709 Procrustes coordinates (digitized onto 21 specimens) to identify the individuals at the extremes of the first three principal components. The FEMs were assigned the material properties of bone and were loaded and constrained to simulate maximal bites on the P(3) and M(2) . Resulting strains indicate that intraspecific cranial variation in morphology is associated with quantitatively high levels of variation in strain magnitudes, but qualitatively little variation in the distribution of strain concentrations. Thus, interspecific comparisons should include considerations of the spatial patterning of strains rather than focus only on their magnitudes.

Full Text

Duke Authors

Cited Authors

  • Smith, AL; Benazzi, S; Ledogar, JA; Tamvada, K; Pryor Smith, LC; Weber, GW; Spencer, MA; Dechow, PC; Grosse, IR; Ross, CF; Richmond, BG; Wright, BW; Wang, Q; Byron, C; Slice, DE; Strait, DS

Published Date

  • January 2015

Published In

Volume / Issue

  • 298 / 1

Start / End Page

  • 122 - 144

PubMed ID

  • 25529239

Pubmed Central ID

  • 25529239

Electronic International Standard Serial Number (EISSN)

  • 1932-8494

International Standard Serial Number (ISSN)

  • 1932-8486

Digital Object Identifier (DOI)

  • 10.1002/ar.23074


  • eng