Mechanical Differences in Skeletons between Primates and Other Common Mammals

本文用异速生长法和主成分分析法对灵长类（包括人）和其他哺乳动物的颅后长骨进行了比较。材料为148种长骨的骨测量数据和40种长骨的横截面几何数据。当通过控制体重进行比较时，非人灵长类动物的肢骨通常比普通哺乳动物的肢骨更长，在骨干和关节面处的直径更大，并且在骨干中部更坚固。在主成分分析中，灵长类明显地从普通哺乳动物中分离出来。许多陆栖灵长类和树栖非灵长类哺乳动物位于这两个群体的边界附近。灵长类动物后肢的粗壮和几个直径特别占优势。人类属于灵长类动物，与普通哺乳动物不同。针对这些差异，指出了灵长类动物在树栖三维空间占优势，而哺乳类动物在陆地二维空间占优势的习惯性位置行为。异速生长指数在长度上接近1/3，在截面模量上接近1.0，表明了弯曲的健壮性。哺乳动物长骨的比例发生了异速生长变化，不是为了抵抗屈曲，而是为了抵抗弯曲。人类在哺乳动物，特别是灵长类动物的这些特征的基础上发展了后肢骨。

Postcranial long bones of primates including humans were compared with those of other common mammals by means of the allometry and the principal component analysis. Materials were long bones of 148 species in the osteometrical data and those of 40 species in the data of the cross-sectional geometry. The limb bones of nonhuman primates were generally longer, larger in diameters both at the shaft and the articular surface, and more robust at the mid-shaft than those of common mammals when the comparisons were made by controlling body mass. Primates clearly made a group separated from the common mammals in the principal component analysis. Many terrestrial primates and arboreal non-primate mammals were situated near the border of the two groups. The robust and several diameter are particularly dominant in the hindlimbs of primates. Humans belong to the primate group and differ from the common mammal group. The habitual positional behavior was pointed out in relation to these differences, that is, the primates live dominantly in the arboreal three-dimensional space and the common mammals on the terrestrial two-dimensional plane. The exponents in allometry were nearly 1/3 in length and 1.0 in the section modulus which indicates the bending robusticity. The proportions of mammalian long bones were allometrically changed not to resist against the buckling but to resist against the bending. Humans developed the hind limb bones on the bases of these characteristics in mammals, especially in primates.