Bastir Markus, Rosas Antonio
Department of Paleobiology, Museo Nacional de Ciencias Naturales, CSIC, 28006 Madrid, Spain.
J Hum Evol. 2004 Nov;47(5):359-81. doi: 10.1016/j.jhevol.2004.08.009.
Facial heights, i.e. the vertical distances between the superior and inferior limits of facial compartments, contribute to the orientation of the viscerocranium in the primate skull. In humans, vertical facial variation is among the main sources of diversity and frequently associated with an integrated suite of other cranio-mandibular traits. Facial heights and kyphosis are also important factors in interspecific variation and models of hominoid evolution. The ontogenetic determination of adult facial orientation and its relation to phylogenetic variation are unclear, but crucial in all previously mentioned respects. We addressed these issues in a sample of 175 humans and chimpanzees with Procrustes based geometric morphometrics, testing hypotheses of interspecific similarity in postnatal ontogenetic trajectories, early versus later ontogenetic facial pattern determination, and a developmental model of morphological integration. We analyzed the contribution of postnatal morphogenesis to adult vertical facial variation by partitioning morphological variation into a portion of pure growth allometry and a non-allometric fraction. A statistically significant difference of growth-allometries revealed that in both species growth established the adult skull proportions by vertical facial expansion, but while in chimpanzees the complete viscerocranium showed reorientation, in humans only the lower face was modified. In both species the results support a hypothesis of early facial pattern determination. A coincident emergence of morphological traits favors a hypothesis of developmental integration of the face, excluding traits of the basi- and neurocranium. Interspecific differences in integration may have implications for evolutionary studies. The present findings indicate that growth establishes the adult skull proportions and integrates principal facial orientation patterns, already there in early postnatal ontogeny.
面部高度，即面部各区域上下边界之间的垂直距离，有助于灵长类动物头骨中面颅的定向。在人类中，面部垂直变异是多样性的主要来源之一，并且经常与一系列其他颅颌特征相关联。面部高度和脊柱后凸也是种间变异和类人猿进化模型中的重要因素。成年后面部定向的个体发育决定及其与系统发育变异的关系尚不清楚，但在上述所有方面都至关重要。我们使用基于普洛卡斯特斯方法的几何形态测量学，对175名人类和黑猩猩样本进行了研究，检验了产后个体发育轨迹种间相似性、个体发育早期与晚期面部模式决定以及形态整合发育模型的假设。我们通过将形态变异划分为纯生长异速生长部分和非异速生长部分，分析了产后形态发生对成年后面部垂直变异的贡献。生长异速生长的统计学显著差异表明，在两个物种中，生长都是通过面部垂直扩展来确定成年头骨比例的，但在黑猩猩中，整个面颅显示出重新定向，而在人类中只有下脸发生了改变。在两个物种中，结果都支持早期面部模式决定的假设。形态特征的同时出现支持了面部发育整合的假设，不包括颅底和脑颅的特征。整合方面的种间差异可能对进化研究有影响。目前的研究结果表明，生长确定了成年头骨比例，并整合了主要的面部定向模式，这些在出生后早期个体发育中就已存在。
