Abstract:
The cranium is widely recognized as the most important skeletal element to use when evaluating
population differences and estimating ancestry. However, the cranium is not always intact or available
for analysis, which emphasizes the need for postcranial alternatives. The purpose of this study was to
quantify postcraniometric differences among South Africans that can be used to estimate ancestry.
Thirty-nine standard measurements from 11 postcranial bones were collected from 360 modern black,
white and coloured South Africans; the sex and ancestry distribution were equal. Group differences were
explored with analysis of variance (ANOVA) and Tukey’s honestly significant difference (HSD) test.
Linear and flexible discriminant analysis (LDA and FDA, respectively) were conducted with bone models
as well as numerous multivariate subsets to identify the model and method that yielded the highest
correct classifications. Leave-one-out (LDA) and k-fold (k = 10; FDA) cross-validation with equal priors
were used for all models. ANOVA and Tukey’s HSD results reveal statistically significant differences
between at least two of the three groups for the majority of the variables, with varying degrees of group
overlap. Bone models, which consisted of all measurements per bone, resulted in low accuracies that
ranged from 46% to 63% (LDA) and 41% to 66% (FDA). In contrast, the multivariate subsets, which
consisted of different variable combinations from all elements, achieved accuracies as high as 85% (LDA)
and 87% (FDA). Thus, when using a multivariate approach, the postcranial skeleton can distinguish
among three modern South African groups with high accuracy.
