Doctoral Dissertation Improvement: The Influences of Brain Anatomy on Facial Positioning in Anthropoid Primates: Implications for Modern Human Origins

本论文的研究目的是探讨灵长类面部骨骼与脑壳解剖关系的变异。特别是，这项研究将测试三个假设，代表非相互排斥的解释相对于头骨的其余部分的面部骨骼的位置。前两个假设认为，灵长类动物面部骨骼的位置是由大脑的解剖结构决定的--分别由大脑的整体大小和颞叶的大小决定。第三个假设代表了一种替代观点，即面部的位置是由大脑的解剖结构决定的，而不是面部骨骼本身的大小决定了它相对于脑壳的位置。这些假设将使用收集的数据进行测试，从数字X光片的头骨和MRI扫描的大脑。假设的预测将使用度量和几何形态测量方法进行评估，系统发育比较方法将被用来调整样本中类群之间的进化关系。这项研究的结果将对理解灵长类动物的颅面结构具有重要意义，并将与理解智人的衍生颅形具有特定的相关性。在本论文的过程中收集的射线照片将发表在一个免费的在线数据库，这将是有用的物理人类学家和其他科学家和教育工作者。 该项目还将支持培养一名有前途的科学家。

This dissertation research will investigate variation in the anatomical relationship of the facial skeleton and the braincase in anthropoid primates. Particularly, this study will test three hypotheses that represent non-mutually exclusive explanations for the position of the facial skeleton relative to the rest of the skull. The first two hypotheses posit that the position of the facial skeleton in anthropoid primates is determined by the anatomy of the brain -- by the overall size of the brain and the size of the temporal lobe, respectively. The third hypothesis represents an alternative to the notion that facial positioning in anthropoids is determined by the anatomy of the brain, and suggests instead that the size of the facial skeleton itself determines its position relative to the braincase. The hypotheses will be tested using data collected from digital radiographs of anthropoid skulls and MRI scans of anthropoid brains. The predictions of the hypotheses will be evaluated using metric and geometric morphometric methods, and phylogenetic comparative methods will be employed to adjust statistically for the evolutionary relationships among the taxa in the sample. The results of this research will have important implications for understanding craniofacial architecture in anthropoid primates and will specific relevance for understanding the derived cranial form of Homo sapiens. The radiographs collected in the course of this dissertation will be published on a free online database that will be useful for physical anthropologists and other scientists and for educators. This project will also support the graduate training of a promising scientist.