Exploring facial gracilization through an integrated approach of mandibular ontogeny: preliminary results from chimpanzees
Texte intégral
1The human face is characterized by a more gracile morphology compared to the more robust features observed in the human fossil record and among our ape relatives. Understanding the mechanisms of growth that lead to adult morphology is key to comprehending the timing and potential causes of the facial changes that occurred during human evolution. Documenting structural changes during ontogeny, such as shape changes, cortical thickening, and bone modeling patterns, can help identify phenotypically plastic features and pinpoint the developmental stages responsible for robusticity and, conversely, gracility. Specifically, this process can be examined by comparing the growth and development of gracile human morphology with the more robust morphology of our closest living relative, the chimpanzee. In this preliminary study, we assess how cortical thickness of the mandible relates to shape changes and bone formation patterns during ontogeny. We examined a sample of 10 chimpanzee mandibles, divided into four age groups. First, we collected mandibular shape data using three-dimensional surface models extracted from microcomputed tomography scans. Next, we generated morphometric maps of cortical thickness across the entire mandible. Finally, we assessed bone formation and resorption patterns using external surface molds of the mandibles. Our preliminary results indicate consistent global patterns in shape changes, cortical thickening, and bone formation rates across ontogeny. However, localized discrepancies were identified, particularly on the buccal side of the symphysis, where high magnitudes of shape changes were observed alongside areas of thin cortical bone. These results suggest that differences in the functional or developmental environment may account for these local variations, which a larger sample size will help to clarify.
Pour citer cet article
Référence électronique
Sélim Natahi, Zewdi J. Tsegai, Alexandra Schuh et Sarah E. Freidline, « Exploring facial gracilization through an integrated approach of mandibular ontogeny: preliminary results from chimpanzees », Bulletins et mémoires de la Société d’Anthropologie de Paris [En ligne], 37(S) | 2025, mis en ligne le 16 janvier 2025, consulté le 13 février 2025. URL : http://journals.openedition.org/bmsap/15207 ; DOI : https://doi.org/10.4000/133p5
Haut de pageDroits d’auteur
Le texte seul est utilisable sous licence CC BY-NC-ND 4.0. Les autres éléments (illustrations, fichiers annexes importés) sont « Tous droits réservés », sauf mention contraire.
Haut de page