Dissertation Research: The Phylogenetic Position of Otavipithecus Namibiensis Quantitative Character Coding in Hominoid Phylogeny Reconstruction

这个项目将分析最近在纳米比亚发现的中新世人科物种纳米比亚奥塔匹猿的进化关系。 中新世的类人猿是一个种类繁多的猿类化石组合，大约在距今2200万到500万年前占据了旧大陆，它既产生了人类，也产生了我们现存的近亲--非洲猿。 因此，了解这些早期猿类的进化关系对于研究人类起源至关重要。 本研究还将解决人科动物研究中的一个具体的方法论问题：数量形态特征在重建人科动物进化关系中的作用。 目前的方法编码成离散字符状态的分支分析和几个新的灵长类动物系统学的方法将被应用到形态测量数据从类人猿下颌骨。 将比较这些方法的相对有效性。 研究样本将包括化石和现存的人科动物下颌骨，这些下颌骨收藏在美国，欧洲和非洲，重点是建立有效的生物样本和最大限度地扩大样本规模。 进化分析将使用目前的计算机辅助方法的生殖重建，和先前所述的假设有关的进化关系的Otavipithecus namibiensis将根据这些结果进行检查。 除了对Otavipithecus的进化亲和力进行详细调查外，这项研究还将首次严格审查数量性状编码在灵长类动物生殖重建中的作用，其结果最终可能推广到人科动物的其他解剖区域以及其他灵长类动物群体的研究。

This project will analyze the evolutionary relationships of Otavipithecus namibiensis, the recently discovered Miocene hominoid species from Namibia. The Miocene hominoids, a diverse assemblage of fossil apes which occupied the Old World from roughly 22 to 5 million years before present, gave rise both to humans and our closest living relatives, the African apes. Consequently, understanding the evolutionary relationships of these early apes is crucial to the study of human origins. This study also will address a specific methodological problem in hominoid studies: the role of quantitative morphological characters in the reconstruction of hominoid evolutionary relationships. Current methods of coding quantitative characters into discrete character states for cladistic analysis and several statistically-based methods new to primate systematics will be applied to morphometric data taken from hominoid mandibles. The relative effectiveness of these methods will be compared. The study sample will comprise fossil and extant hominoid mandibles housed in collections in the U.S., Europe, and Africa, with an emphasis on constructing valid biological samples and maximizing sample sizes. Evolutionary analysis will be performed using current computer-assisted methods of phylogeny reconstruction, and previously stated hypotheses concerning the evolutionary relationships of Otavipithecus namibiensis will be examined in the light of these results. In addition to being a detailed investigation of the evolutionary affinities of Otavipithecus, this study will provide the first rigorous examination of the role of quantitative character coding in primate phylogeny reconstruction, the results of which ultimately may be generalized to additional anatomical regions in hominoids, as well as to studies of other primate groups.