周口店第一地点人类牙齿化石的时序性变异

周口店第一地点人类下颌牙齿材料显示出一定程度的时序性变异。该地点时代较晚的下颌牙齿与时代较早的相比，门齿偏大些，而犬齿和犬齿后各齿显得偏小，呈现出趋向早期智人牙齿尺寸格式的演变。该地点人类牙齿大小上的差异不能如魏敦瑞所主张的那样单纯地归因于两性差异。

AN EXAMINATION OF TEMPORAL VARIATION IN THE HO-MINID DENTAL SAMPLE FROM ZHOUKOUDIAN LOCALITY 1

More than 50 years ago, in his publications on human fossils from Zhoukoudian Locality 1, Weidenreich argued that "the difference in size of Sinanthropus teeth is a sexual one" (Weidenreich, 1935) and "the large type of teeth belong to male individuals and the small to females" (Weidenreich, 1937). He concluded: "The morphological character of the Sinanthropus population of Locality 1, therefore, remained unchanged during the long periods of time necessary for the filling-up of the cave" (Weidenreich, 1935).In this paper, a comparison of the teeth from upper layers with those from lower ones shows that a temporal variation is also responsible for the difference in size of the teeth from this site. The temporal variation can be seen in mandibular teeth. Over the timespan from 500 to 230 Ky B.P, the lower incisors tend to be larger whereas the lower canines and postcanines to be smaller. The P3 reduces less than the P4, and the M1 reduces less than the other molars. An evolutionary change in direction of early Homo sapiens condition is suggested in the dental sample from Zhoukoudian Locality 1.