The contribution of size and shape variation to patterns of sexual dimorphism of the human femur.

Abstract

AbstractThe present research was undertaken to determine the relationship between patterns of generalized intrapopulational variation determined from principal components analysis and patterns of sexual dimorphism determined from Student's t and discriminant function analysis. The analysis was based upon 17 measurements of 97 femurs from a Middle Mississippian Amerindian population. The results of the principal components analysis indicated that the 17 original measurements could be represented as four principal component variates. Inspection of component loadings lent support to the contention that the first principal component reflected variation in general size while components two to four reflected variation in femoral shape.Analysis of the relationship between principal component loading and male‐female differences reflected in Student's t demonstrated a high (0.97) positive correlation between absolute magnitude of loading in the first principal component and magnitude of Student's t. As a result, discriminant analyses of the femur, utilizing univariate criteria for the inclusion of variables, have been biased in the direction of size variation. Subsequent stepwise discriminant function analyses demonstrated that an adequate discriminant model must reflect all dimensions of morphological variation at the intrapopulational level.