Multivariate analysis of relative growth in the limb bones of Arikara Indians.

The description of relative growth in the limb bones of Arikara Indians from a large archeological sample (N = 412 nonadults) is approached by (1) using a multivariate generalization of the bivariate scaling relationship, and (2) extracting the principal components of log shape. The two methods are shown to be complementary, and advantages accrue to both. Although most of the variability among individuals is related primarily to differences in size, significant age-related differences in shape are disclosed by both approaches. Negative forelimb growth allometry contrasts with positive hind limb allometry and results in decreasing intermembral indices with changing size and age. A within-limb, disto-proximal growth gradient is also evident, inasmuch as the proximal element within each limb grows faster than the distal. A functional link to the human specialization for bipedal locomotion and posture is apparent. A comparison between the ontogenetic results of this study and those from an analysis of static adult scaling from the same populations discloses no similarities between the two and suggests that one type of data cannot be substituted for the other.