Geographic variation in Native American anthropometrics: A spatial analysis of the Boas and Gifford datasets

Paul Christopher Dillingham
Dept. of Anthropology, University of Tennessee
July, 2005


A more comprehensive spatial analysis of the Boas and Gifford datasets was undertaken because previous studies of this type either were not published or utilized no statistical analyses. Therefore, the purpose of this study is to more comprehensively re-analyze the Boas and Gifford datasets using spatial analysis methods to discover the patterns of variation revealed by the data. The following questions were addressed. First, is there significant heterogeneity in the anthropometric data? Second, what spatial patterns are revealed by the data?
Third, do the data show significant spatial structure? Fourth, do the patterns revealed by the analysis show evidence of the migration or migrations that brought Native Americans to the New World? Fifth, what influence did language have on the variation displayed in the Boas and Gifford datasets? The sample sizes consisted of 9024 individuals subdivided into 120 populations for the head dimensions and 8445 individuals spread over 119 populations for the body dimensions. The variables used in the analysis consisted of 12 anthropometric dimensions and 2 additional dimensions, arm length, calculated by subtracting finger height from shoulder height, and leg length, calculated by subtracting sitting height from standing height. The head and body measurements were analyzed separately. A variety of univariate and multivariate methods were used to address the above questions. For the spatial autocorrelation analysis, Moran's I and Geary's coefficients were calculated. Both one- and two-dimensional correlograms were constructed. Matrix correlation analysis was utilized to assess the influence of language on the variation of the data. In order to check for boundaries to gene flow, Wombling analysis was applied to the data.
The results of the analyses revealed little linguistic patterning in the head data, but it was revealed in the body data. Overall, the results showed that the head data produced little evidence for inter-continental migrations, but the body data revealed evidence for at least one such migration. In addition, a complex network of gene drift, regional gene flow, and natural selection was mainly responsible for the variation in the data.