Nicholson Elisabeth, Harvati Katerina
Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois 60611-3008, USA.
Am J Phys Anthropol. 2006 Nov;131(3):368-83. doi: 10.1002/ajpa.20425.
Human mandibular morphology is often thought to reflect mainly function, and to be of lesser value in studies of population history. Previous descriptions of human mandibles showed variation in ramal height and breadth to be the strongest difference among recent human groups. Several mandibular traits that differentiate Neanderthals from modern humans include greater robusticity, a receding symphysis, a large retromolar space, a rounder gonial area, an asymmetric mandibular notch, and a posteriorly positioned mental foramen in Neanderthals. Nevertheless, the degree to which these differences are part of modern human variation and/or are related to size and function remains unclear. The aim of this study was to document geographic and functional patterning in the mandibular shape of recent humans, to assess the effects of allometry on mandibular form, and to quantitatively evaluate proposed "Neanderthal" mandibular traits through comparison with samples of geographically diverse recent humans. Data were collected in the form of three-dimensional coordinates of 28 landmarks. Unlike previous studies, this analysis found that modern human mandibular shape exhibits considerable geographic patterning, with some aspects of mandibular morphology reflecting a climatic gradient, and others, a functional specialization. Population history is also reflected in mandibular form, albeit relatively weakly. Proposed "Neanderthal" traits were found to separate Neanderthal from modern human mandibles successfully in the statistical analysis. Of these, the retromolar gap was found to be related to increased mandibular size in modern humans. The status of this trait as a Neanderthal autapomorphy should therefore be treated with caution.
人类下颌形态通常被认为主要反映功能，在群体历史研究中的价值较小。先前对人类下颌骨的描述表明，下颌支高度和宽度的差异是现代人类群体之间最显著的差异。一些区分尼安德特人与现代人类的下颌特征包括更强壮、下颌联合后缩、磨牙后间隙大、下颌角更圆、下颌切迹不对称以及尼安德特人的颏孔位置靠后。然而，这些差异在多大程度上是现代人类变异的一部分和/或与大小和功能相关仍不清楚。本研究的目的是记录现代人类下颌形状的地理和功能模式，评估异速生长对下颌形态的影响，并通过与来自不同地理区域的现代人类样本进行比较，定量评估所提出的“尼安德特人”下颌特征。数据以28个地标点的三维坐标形式收集。与先前的研究不同，本分析发现现代人类下颌形状呈现出相当大的地理模式，下颌形态的某些方面反映了气候梯度，而其他方面则反映了功能特化。群体历史也反映在下颌形态中，尽管相对较弱。在统计分析中，所提出的“尼安德特人”特征被发现能够成功地将尼安德特人的下颌骨与现代人类的下颌骨区分开来。其中，磨牙后间隙被发现与现代人类下颌大小的增加有关。因此，应谨慎对待这一特征作为尼安德特人独征的地位。
