Race and global patterns of phenotypic variation |
Race and global patterns of phenotypic variation
American Journal of Physical Anthropology
Volume 139, Issue 1 (May 2009) Special Issue: Race Reconciled: How Biological Anthropologists View Human Variation
pages 16–22
DOI: 10.1002/ajpa.20900
John H. Relethford, Distinguished Teaching Professor of Anthropology
State University of New York, Oneonta
Phenotypic traits have been used for centuries for the purpose of racial classification. Developments in quantitative population genetics have allowed global comparison of patterns of phenotypic variation with patterns of variation in classical genetic markers and DNA markers. Human skin color shows a high degree of variation among geographic regions, typical of traits that show extensive natural selection. Even given this high level of geographic differentiation, skin color variation is clinal and is not well described by discrete racial categories. Craniometric traits show a level of among-region differentiation comparable to genetic markers, with high levels of variation within populations as well as a correlation between phenotypic and geographic distance. Craniometric variation is geographically structured, allowing high levels of classification accuracy when comparing crania from different parts of the world. Nonetheless, the boundaries in global variation are not abrupt and do not fit a strict view of the race concept; the number of races and the cutoffs used to define them are arbitrary. The race concept is at best a crude first-order approximation to the geographically structured phenotypic variation in the human species.
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Tags: American Journal of Physical Anthropology, John H. Relethford, John Relethford