Climatic adaptation in human inferior nasal turbinate morphology: Evidence from Arctic and equatorial populations

Tarah N. Marks, Scott David Maddux, Lauren N. Butaric, Robert G. Franciscus

Research output: Contribution to journalArticle

Abstract

Objectives: The nasal turbinates directly influence the overall size, shape, and surface area of the nasal passages, and thus contribute to intranasal heat and moisture exchange. However, unlike the encapsulating walls of the nasal cavity, ecogeographic variation in nasal turbinate morphology among humans has not yet been established. Here we investigate variation in inferior nasal turbinate morphology in two populations from climatically extreme environments. Materials and methods: Twenty-three linear measurements of the inferior turbinate, nasal cavity walls, and airway passages were collected from CT scans of indigenous modern human crania from Equatorial Africa (n = 35) and the Arctic Circle (n = 35). MANOVA and ANCOVA were employed to test for predicted regional and sex differences in morphology between the samples. Results: Significant morphological differences were identified between the two regional samples, with no evidence of significant sexual dimorphism or region-sex interaction effect. Individuals from the Arctic Circle possessed superoinferiorly and mediolaterally larger inferior turbinates compared to Equatorial Africans. In conjunction with the surrounding nasal cavity walls, these differences in turbinate morphology produced airway dimensions that were both consistent with functional expectations and more regionally distinct than either skeletal component independently. Conclusion: This study documents the existence of ecogeographic variation in human nasal turbinate morphology reflecting climate-mediated evolutionary demands on intranasal heat and moisture exchange. Humans adapted to cold-dry environments exhibit turbinate morphologies that enhance contact between respired air and nasal mucosa to facilitate respiratory air conditioning. Conversely, humans adapted to hot-humid environments exhibit turbinate morphologies that minimize air-to-mucosa contact, likely to minimize airflow resistance and/or facilitate expiratory heat-shedding.

Original languageEnglish
Pages (from-to)498-512
Number of pages15
JournalAmerican Journal of Physical Anthropology
Volume169
Issue number3
DOIs
StatePublished - 1 Jul 2019

Fingerprint

Turbinates
Arctic
Nose
Population
evidence
heat
Nasal Cavity
air
Hot Temperature
Sex Characteristics
contact
Air
Air Conditioning
conditioning
Nasal Mucosa
Climate
Skull
climate
Mucous Membrane
interaction

Keywords

  • conchae
  • human variation
  • nose
  • respiratory tract
  • thermoregulation

Cite this

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title = "Climatic adaptation in human inferior nasal turbinate morphology: Evidence from Arctic and equatorial populations",
abstract = "Objectives: The nasal turbinates directly influence the overall size, shape, and surface area of the nasal passages, and thus contribute to intranasal heat and moisture exchange. However, unlike the encapsulating walls of the nasal cavity, ecogeographic variation in nasal turbinate morphology among humans has not yet been established. Here we investigate variation in inferior nasal turbinate morphology in two populations from climatically extreme environments. Materials and methods: Twenty-three linear measurements of the inferior turbinate, nasal cavity walls, and airway passages were collected from CT scans of indigenous modern human crania from Equatorial Africa (n = 35) and the Arctic Circle (n = 35). MANOVA and ANCOVA were employed to test for predicted regional and sex differences in morphology between the samples. Results: Significant morphological differences were identified between the two regional samples, with no evidence of significant sexual dimorphism or region-sex interaction effect. Individuals from the Arctic Circle possessed superoinferiorly and mediolaterally larger inferior turbinates compared to Equatorial Africans. In conjunction with the surrounding nasal cavity walls, these differences in turbinate morphology produced airway dimensions that were both consistent with functional expectations and more regionally distinct than either skeletal component independently. Conclusion: This study documents the existence of ecogeographic variation in human nasal turbinate morphology reflecting climate-mediated evolutionary demands on intranasal heat and moisture exchange. Humans adapted to cold-dry environments exhibit turbinate morphologies that enhance contact between respired air and nasal mucosa to facilitate respiratory air conditioning. Conversely, humans adapted to hot-humid environments exhibit turbinate morphologies that minimize air-to-mucosa contact, likely to minimize airflow resistance and/or facilitate expiratory heat-shedding.",
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Climatic adaptation in human inferior nasal turbinate morphology : Evidence from Arctic and equatorial populations. / Marks, Tarah N.; Maddux, Scott David; Butaric, Lauren N.; Franciscus, Robert G.

In: American Journal of Physical Anthropology, Vol. 169, No. 3, 01.07.2019, p. 498-512.

Research output: Contribution to journalArticle

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T1 - Climatic adaptation in human inferior nasal turbinate morphology

T2 - Evidence from Arctic and equatorial populations

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AU - Maddux, Scott David

AU - Butaric, Lauren N.

AU - Franciscus, Robert G.

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