Absolute humidity and the human nose: A reanalysis of climate zones and their influence on nasal form and function
Dados Bibliográficos
| AUTOR(ES) | |
|---|---|
| AFILIAÇÃO(ÕES) | University of North Texas, Department of Anthropology, Department of Orthodontics University of Iowa 114 Macbride Hall Iowa City Iowa 52242, Department of Sociology and Anthropology Metropolitan State University of Denver Denver Colorado 80217, Department of Soil, Environmental and Atmospheric Sciences University of Missouri Columbia Missouri 65212 |
| ANO | 2016 |
| TIPO | Artigo |
| PERIÓDICO | American Journal of Physical Anthropology |
| ISSN | 0002-9483 |
| E-ISSN | 1096-8644 |
| EDITORA | John Wiley and Sons Inc |
| DOI | 10.1002/ajpa.23032 |
| CITAÇÕES | 8 |
| ADICIONADO EM | 2025-08-18 |
| MD5 |
0a6b51e411c836160e8eccbffe7f9a02
|
Resumo
ObjectivesInvestigations into the selective role of climate on human nasal variation commonly divide climates into four broad adaptive zones (hot‐dry, hot‐wet, cold‐dry, and cold‐wet) based on temperature and relative humidity. Yet, absolute humidity—not relative humidity—is physiologically more important during respiration. Here, we investigate the global distribution of absolute humidity to better clarify ecogeographic demands on nasal physiology.MethodsWe use monthly observations from the Climatic Research Unit Timeseries 3 (CRU TS3) database to construct global maps of average annual temperature, relative humidity and absolute humidity. Further, using data collected by Thomson and Buxton (1923) for over 15,000 globally‐distributed individuals, we calculate the actual amount of heat and water that must be transferred to inspired air in different climatic regimes to maintain homeostasis, and investigate the influence of these factors on the nasal index.ResultsOur results show that absolute humidity, like temperature, generally decreases with latitude. Furthermore, our results demonstrate that environments typically characterized as 'cold‐wet' actually exhibit low absolute humidities, with values virtually identical to cold‐dry environments and significantly lower than hot‐wet and even hot‐dry environments. Our results also indicate that strong associations between the nasal index and absolute humidity are, potentially erroneously, predicated on individuals from hot‐dry environments possessing intermediate (mesorrhine) nasal indices.DiscussionWe suggest that differentially allocating populations to cold‐dry or cold‐wet climates is unlikely to reflect different selective pressures on respiratory physiology and nasal morphology—it is cold‐dry, and to a lesser degree hot‐dry environments, that stress respiratory function. Our study also supports assertions that demands for inspiratory modification are reduced in hot‐wet environments, and that expiratory heat elimination for thermoregulation is a greater selective pressure in such environments.