“高资人”化石与股骨形态变异的生物力学分析

运用生物力学方法对1980年在江苏镇江高资镇采集的2件完全石化的人类股骨进行分析,并在常规形态观测和加速器质谱14C测年的基础上对更新世人类化石及全新世现代人股骨形态的变异进行讨论.测年数据显示,"高资人"股骨可能属于全新世现代智人,但基于CT扫描数据计算出的骨干抗压抗拉强度、抗弯强度及其他形态特征都呈现某些较全新世现代人更显古老的特征.对比分析表明,人类股骨形态及测量值因其功能状况等原因具有相当大的变异,股骨形态特征不能作为判断化石系统发育地位的最关键证据.股骨生物力学参数是其功能状况的直接反映,在人类不同演化阶段因运动行为模式差异,其相对大小在不同人群存在更加明显分异,因而生物力学分析在长骨功能状况研究上具有很大应用价值.化石石化程度不是判断其年代的可靠标准.

Biochemical analysis and morphological variation of Gaozi human fossil femurs

A biomechanical method was used to analyze two incomplete heavily fossilized human femur fossils collected from Gaozi,Jiangsu Province,China.Direct AMS 14 C reveal the fossils were ca.1350 years old.Morphological and biomechanical comparisons were made to examine the variation of morphology from the human femurs.When these Gaozi femurs were compared in cross sections,they showed robust diameters,cortical bone areas and anti-bending strength.Our measurements as well as some morphological characters suggest the fossils were more primitive than most modern Holocene populations.This indicates that the morphology and measurements of Homo sapiens femurs have a great range of variation and should not be used as key evidence for phylogenetic analysis.The morphological differentiation of human femurs is better represented from relative biomechanical parameters,which may indicate functional differences in different kinds of human fossils.Biomechanical analysis provides direct information of long bone functional status that may have great value in functional studies of postcranial bones.In addition,we found that the degree of fossilization is not a good indicator of age.In China,some fossils were not found in situ and have no direct dating result,therefore the creditability of their presumed age should be carefully considered.