Related Experiment Video
Updated: Aug 10, 2025
08:15
Reverse Dissection and DiceCT Reveal Otherwise Hidden Data in the Evolution of the Primate Face
Published on: January 7, 2019
7.0K
Craniofacial fluctuating asymmetry in gorillas, chimpanzees, and macaques
Ashly N Romero1, D Rex Mitchell2, Siobhán B Cooke3
1Department of Anthropology, University of Arkansas, Fayetteville, Arkansas, USA.
American Journal of Biological Anthropology
|February 15, 2023
Summary
Craniofacial fluctuating asymmetry (FA) in nonhuman primates reveals developmental instability patterns. Chimpanzees showed the most developmental stability, while gorillas and macaques exhibited higher FA, suggesting potential environmental influences.
Area of Science:
- Primatology
- Evolutionary Biology
- Developmental Biology
Background:
- Craniofacial fluctuating asymmetry (FA) quantifies random deviations from bilateral symmetry.
- FA serves as a proxy for developmental instability in organisms.
- Data on craniofacial FA in nonhuman primates is limited.
Purpose of the Study:
- To analyze FA magnitude and variation in chimpanzees, gorillas, and macaques.
- To investigate FA as a measure of developmental instability within and among nonhuman primate taxa.
- To address the scarcity of craniofacial FA data in nonhuman primates.
Main Methods:
- Generated 3D surface models of 121 crania from three primate species.
- Employed geometric morphometric techniques to calculate FA magnitude.
- Compared FA across individuals, sexes, taxa, cranial regions, and landmarks.
Main Results:
- Gorillas and macaques displayed higher and similar FA magnitudes compared to chimpanzees.
- FA variation followed similar trends across taxa.
- No significant sex differences in pooled data, but sex influenced FA in gorillas.
Conclusions:
- Chimpanzees in this sample may possess the greatest developmental stability.
- Environmental factors like growth rate and stress could explain FA patterns.
- Identified key landmarks for future FA studies and potential conservation priorities.
