Collaborative research: A histological and CT study of midfacial growth trajectories in subadult primates

University Of Florida, Gainesville FL

Investigators

Abstract

Primates are distinguished from most other mammals by a trend toward midfacial reduction, most notably seen in the reduced 'snout' of monkeys, apes, and humans. This study uses a novel developmental approach to test whether midfacial reduction of the skull in primates is a byproduct of growth of neighboring structures (e.g., eyes and teeth). For example, does selection for a precocious visual nervous system fundamentally affect midfacial patterns of growth? Do proportionately large deciduous maxillary teeth and their successors have transient or lasting effects on development of paranasal spaces of the maxilla? To answer these questions, cadaveric samples from over seventy specimens (including 20 species of primates) will be studied. Specimens of different postnatal ages will be studied using an innovative combination of high-resolution computed tomography (CT) and microscopic study of decalcified samples. The result is a novel approach for mapping regions of bone deposition and resorption in three dimensions. The project will create unique three-dimensional 'growth maps' of primate skulls in relation to functional units of the head (eyes, nasal airways, teeth). Three-dimensional skull form and growth maps will then be compared among primates that differ in the extent to which the eyes are convergent (forward-facing). Indirect influences on neural and dental development, such as gestation length and diet, will also be used as variables. The broader implications of the study include a web-based atlas and digital archive of histological and CT images from the specimens. The interactive online atlas will be developed as a resource for anatomists, who will benefit from animal models for aspects of human development, and primatologists, who will benefit from the resource on development of primates. In addition, animations which highlight the importance of growth mechanisms for evolutionary adaptation will be created and made available to advanced K-12 students and their teachers as online educational tools.