Abstract
Objectives: Although the internal nose is overwhelmingly responsible for heat and moisture exchange during respiration, external nasal morphology is more commonly cited as evincing climatic adaptation in humans. Here, we assess variation across all four morphofunctional units of the complete nasorespiratory tract (external pyramid, nasal aperture, internal nasal fossa, and nasopharynx) to determine which units provide the strongest evidence of climatic adaptation. Materials and Methods: We employ 20 linear measurements collected on 837 modern human crania from major geographic (Arctic Circle, Asia, Australia, Europe, Africa) and climatic (polar, temperate, hot-arid, tropical) zones. In conjunction with associated climatic and geographic data, these morphological data are employed in multivariate analyses to evaluate the associations between each of these functional nasal units and climate. Results: The external pyramid and nasopharynx exhibit virtually no evidence of climate-mediated morphology across the regional samples, while apparent associations between climate and nasal aperture morphology appear influenced by the geographic (and likely genetic) proximities of certain populations. Only the internal nasal fossa exhibits an ecogeographic distribution consistent with climatic adaptation, with crania from colder and/or drier environments displaying internal nasal fossae that are longer, taller, and narrower (especially superiorly) compared to those from hotter and more humid environments. Conclusions: Our study indicates that the internal nasal fossa exhibits a stronger association with climate compared to other aspects of the human nose. Further, our study supports suggestions that regional variation in internal nasal fossa morphology reflects demands for heat and moisture exchange via adjustment of internal nasal airway dimensions. Our study thus provides empirical support for theoretical assertions related to nasorespiratory function, with important implications for understanding human nasal evolution.
| Original language | English |
|---|---|
| Pages (from-to) | 103-119 |
| Number of pages | 17 |
| Journal | American Journal of Physical Anthropology |
| Volume | 162 |
| Issue number | 1 |
| DOIs | |
| State | Published - 1 Jan 2017 |
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Keywords
- air conditioning
- climatic adaptation
- human evolution
- respiration
- thermoregulation
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Ecogeographic variation across morphofunctional units of the human nose. / Maddux, Scott David; Butaric, Lauren N.; Yokley, Todd R.; Franciscus, Robert G.
In: American Journal of Physical Anthropology, Vol. 162, No. 1, 01.01.2017, p. 103-119.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Ecogeographic variation across morphofunctional units of the human nose
AU - Maddux, Scott David
AU - Butaric, Lauren N.
AU - Yokley, Todd R.
AU - Franciscus, Robert G.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - Objectives: Although the internal nose is overwhelmingly responsible for heat and moisture exchange during respiration, external nasal morphology is more commonly cited as evincing climatic adaptation in humans. Here, we assess variation across all four morphofunctional units of the complete nasorespiratory tract (external pyramid, nasal aperture, internal nasal fossa, and nasopharynx) to determine which units provide the strongest evidence of climatic adaptation. Materials and Methods: We employ 20 linear measurements collected on 837 modern human crania from major geographic (Arctic Circle, Asia, Australia, Europe, Africa) and climatic (polar, temperate, hot-arid, tropical) zones. In conjunction with associated climatic and geographic data, these morphological data are employed in multivariate analyses to evaluate the associations between each of these functional nasal units and climate. Results: The external pyramid and nasopharynx exhibit virtually no evidence of climate-mediated morphology across the regional samples, while apparent associations between climate and nasal aperture morphology appear influenced by the geographic (and likely genetic) proximities of certain populations. Only the internal nasal fossa exhibits an ecogeographic distribution consistent with climatic adaptation, with crania from colder and/or drier environments displaying internal nasal fossae that are longer, taller, and narrower (especially superiorly) compared to those from hotter and more humid environments. Conclusions: Our study indicates that the internal nasal fossa exhibits a stronger association with climate compared to other aspects of the human nose. Further, our study supports suggestions that regional variation in internal nasal fossa morphology reflects demands for heat and moisture exchange via adjustment of internal nasal airway dimensions. Our study thus provides empirical support for theoretical assertions related to nasorespiratory function, with important implications for understanding human nasal evolution.
AB - Objectives: Although the internal nose is overwhelmingly responsible for heat and moisture exchange during respiration, external nasal morphology is more commonly cited as evincing climatic adaptation in humans. Here, we assess variation across all four morphofunctional units of the complete nasorespiratory tract (external pyramid, nasal aperture, internal nasal fossa, and nasopharynx) to determine which units provide the strongest evidence of climatic adaptation. Materials and Methods: We employ 20 linear measurements collected on 837 modern human crania from major geographic (Arctic Circle, Asia, Australia, Europe, Africa) and climatic (polar, temperate, hot-arid, tropical) zones. In conjunction with associated climatic and geographic data, these morphological data are employed in multivariate analyses to evaluate the associations between each of these functional nasal units and climate. Results: The external pyramid and nasopharynx exhibit virtually no evidence of climate-mediated morphology across the regional samples, while apparent associations between climate and nasal aperture morphology appear influenced by the geographic (and likely genetic) proximities of certain populations. Only the internal nasal fossa exhibits an ecogeographic distribution consistent with climatic adaptation, with crania from colder and/or drier environments displaying internal nasal fossae that are longer, taller, and narrower (especially superiorly) compared to those from hotter and more humid environments. Conclusions: Our study indicates that the internal nasal fossa exhibits a stronger association with climate compared to other aspects of the human nose. Further, our study supports suggestions that regional variation in internal nasal fossa morphology reflects demands for heat and moisture exchange via adjustment of internal nasal airway dimensions. Our study thus provides empirical support for theoretical assertions related to nasorespiratory function, with important implications for understanding human nasal evolution.
KW - air conditioning
KW - climatic adaptation
KW - human evolution
KW - respiration
KW - thermoregulation
UR - http://www.scopus.com/inward/record.url?scp=84989237385&partnerID=8YFLogxK
U2 - 10.1002/ajpa.23100
DO - 10.1002/ajpa.23100
M3 - Article
VL - 162
SP - 103
EP - 119
JO - American Journal of Physical Anthropology
JF - American Journal of Physical Anthropology
SN - 0002-9483
IS - 1
ER -