Dissertation Research: Correlates of Variation in Cranial Base Flexion and Facial Positioning in African Apes, Modern Humans and Early Hominids

该项目的目的是记录和解释早期原始人类颅面复合体的两个关键特征的进化变化：1）颅底的成角（屈曲）和2）面部相对于颅底的位置。 虽然人们通常认为这些特征是一起进化的，但以前的研究并没有充分量化它们。 面部定位和颅底弯曲的新测量将从肯尼亚和南非的原始化石中收集。 这样的测量将提高我们对这些关键颅骨特征变化模式的理解。 以前的作者认为，屈曲和面部定位的进化变化是继发于颅骨组成部分（如大脑和咀嚼器）的形状和相对大小的变化。使用现代人类和非洲猿颅骨的比较样本，将测试这些颅骨组件的整体和相对大小与屈曲和面部定位变化相关的假设。 该项目的结果将有助于解释头骨化石之间的差异，并将特别有助于解释我们自己属中密切相关物种之间的进化变化。

The purpose of this project is to document and explain evolutionary changes in two critical features of the early hominid cranio-facial complex: 1) the angulation (flexion) of the cranial base and 2) the position of the face relative to the cranial base. Although it is often assumed that these features evolved together, previous studies have not adequately quantified them. New measurements of facial positioning and cranial base flexion will be collected from original fossils housed in Kenya and South Africa. Such measurements will improve our understanding of the pattern of change in these key cranial features. Previous authors have suggested that evolutionary changes in flexion and facial positioning are secondary to changes in the shape and relative size of skull components such as the brain and masticatory apparatus. Using comparative samples of modern human and African ape crania, hypotheses relating the overall and relative size of these cranial components to variation in flexion and facial positioning will be tested. The results of this project will aid interpretation of variation among fossil crania and will be especially useful in explaining evolutionary changes among closely related species in our own genus.