| This dissertation focused on the comparative study of the human nose and paranasal sinuses (nasal complex) in order to better understand its place among mammals and to assess specific features of the human condition. The research design included a three-phase approach. First, a preliminary investigation focused on the nasal region in terrestrial mammals and extant humans by dissection, endoscopic examination and computer tomography (CT) imaging. Second, a morphometric and CT examination was done of the effects of climate on the nasal complex of closely related macaque species living at high and low altitudes, thus serving as a natural experiment. Third, a quantitative and qualitative study of two extinct hominins---an "archaic Homo sapiens" (Kabwe) and a classic Neanderthal (Gibraltar 1)---was undertaken in order to compare their nasal regions to a large sample of regionally distinct modern populations.; Results from phase 1 showed considerable inter-species variation with regard to the size of the bony elements surrounding the nasal cavity and paranasal sinuses and in the specific configurations of its boundaries. Assessment of the nasal complex in humans revealed that the advent of new imaging modalities is providing a more detailed and precise understanding of specific aspects of the region than previously available. Results from phase 2 showed that the use of internal nasal features greatly enhanced our appreciation of nasal complex anatomy. Results also showed specific effects of climate on different components of the nasal complex. Lastly, results on the nasal complex in fossil hominins and extant humans showed that Neanderthals were distinct from both archaic and modern Homo sapiens having external and internal nasal features consistently and significantly falling outside the ranges of these groups. These data suggest that the nasal complex in particular, the entire respiratory tract in general, in Neanderthals may have been considerably different from that found in archaic and modern Homo sapiens. The results of this study support a species level distinction for Homo neanderthalensis.; The three-phase approach permitted the utilization and integration of different methodologies which allowed both external and internal parameters of the nasal region to be examined for the first time. This approach has provided a more complete perspective upon the function and evolution of a major component of the upper respiratory tract. |
