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Variation in human nasal height and breadth.
1Department of Anthropology, University of New Mexico, Albuquerque 87131.
American Journal of Physical Anthropology
|August 1, 1991
Summary
Human nasal index variation is not spurious. New analysis shows nasal breadth variation is greater within populations, supporting its role in adaptation and human evolution.
Area of Science:
- Anthropology
- Human Evolution
- Bioarchaeology
Background:
- The human nasal index (nasal breadth/nasal height) is linked to climate, but this association is debated.
- Previous arguments against natural selection on nasal index variation focused on nasal breadth's low variability.
Purpose of the Study:
- To re-evaluate the variability of human nasal breadth and height.
- To test the hypothesis that nasal breadth contributes little to human nasal index variation.
Main Methods:
- Analysis of skeletal nasal breadth and height from 2,408 individuals across 26 diverse populations.
- Utilized 2x2 variance-covariance matrices of logarithmically transformed data.
- Applied hypothesis tests for matrix homogeneity and equal variance/covariance.
Main Results:
- Intrinsic variation in nasal breadth is greater than nasal height within populations.
- Nasal breadth and nasal height show equivalent intrinsic variation among populations.
- The argument that nasal breadth has minimal impact on global nasal index variation is rejected.
Conclusions:
- Findings support, but do not confirm, an adaptive role for human nasal index variation.
- Suggests further research into natural selection on human nasal form is warranted.