This research proposal seeks to understand the effects of climate on the structure of the nasal complex by examining the crania of two similar non-human primate groups, Macaca fascicularis and Macaca mulatta, that inhabit different environments. A deeper understanding of the nasal complex (nose, nasal cavity, and paranasal sinuses) is essential for the testing of hypotheses regarding its functional adaptation and evolution in primates. Previous studies on the effects of climate have usually been limited to external craniofacial landmarks. This study approaches the question by assessing data from both internal dimensions and volumes in combination with more traditional external measures. It is hypothesized that there will be significant osteological differences in nasal complex morphology for macaques inhabiting different climates. These differences may reflect the accommodation of respiratory mucosa, the primary modifier of inspired air. Methods to be used will include: 1) linear measurements using traditional anthropological techniques; 2) a seed-filling method that permits volumetric assessment of the maxillary sinus and nasal cavity to yield estimates of the respiratory mucosal area; and 3) the application of new advances in CT-imaging which will allow both for precise visualizations of internal nasal components, and permit measurements of their surface areas. This study will provide new insight for understanding the functional adaptations of the nasal complex in primates, especially in regard to interactions between climate and respiratory demands. The use of new methodologies for assessing nasal volume and CT-scanning for determining internal surface areas, coupled with traditional craniometric measures, will provide a more in depth, multidimensional approach than attempted previously.
