These authors contributed equally to this work.
Genetic, geographic, and environmental correlates of human temporal bone variation
Version of Record online: 13 JUL 2007
Copyright © 2007 Wiley-Liss, Inc.
American Journal of Physical Anthropology
Volume 134, Issue 3, pages 312–322, November 2007
How to Cite
Smith, H. F., Terhune, C. E. and Lockwood, C. A. (2007), Genetic, geographic, and environmental correlates of human temporal bone variation. Am. J. Phys. Anthropol., 134: 312–322. doi: 10.1002/ajpa.20671
- Issue online: 11 OCT 2007
- Version of Record online: 13 JUL 2007
- Manuscript Accepted: 8 MAY 2007
- Manuscript Received: 12 DEC 2006
- AMNH Collections Study Grant and ASU Department of Anthropology. Grant Number: NSF BCS-9982022
- geometric morphometrics;
- molecular distance;
- cranial morphology
Temporal bone shape has been shown to reflect molecular phylogenetic relationships among hominoids and offers significant morphological detail for distinguishing taxa. Although it is generally accepted that temporal bone shape, like other aspects of morphology, has an underlying genetic component, the relative influence of genetic and environmental factors is unclear. To determine the impact of genetic differentiation and environmental variation on temporal bone morphology, we used three-dimensional geometric morphometric techniques to evaluate temporal bone variation in 11 modern human populations. Population differences were investigated by discriminant function analysis, and the strength of the relationships between morphology, neutral molecular distance, geographic distribution, and environmental variables were assessed by matrix correlation comparisons. Significant differences were found in temporal bone shape among all populations, and classification rates using cross-validation were relatively high. Comparisons of morphological distances to molecular distances based on short tandem repeats (STRs) revealed a significant correlation between temporal bone shape and neutral molecular distance among Old World populations, but not when Native Americans were included. Further analyses suggested a similar pattern for morphological variation and geographic distribution. No significant correlations were found between temporal bone shape and environmental variables: temperature, annual rainfall, latitude, or altitude. Significant correlations were found between temporal bone size and both temperature and latitude, presumably reflecting Bergmann's rule. Thus, temporal bone morphology appears to partially follow an isolation by distance model of evolution among human populations, although levels of correlation show that a substantial component of variation is unexplained by factors considered here. Am J Phys Anthropol 2007. © 2007 Wiley-Liss, Inc.