Doctoral Dissertation: Neandertal Dental Morpology: Implications for Modern Human Origins

这项研究的目的是通过首次从进化角度对晚更新世古人类牙齿形态进行系统的比较研究，揭示解剖学上现代人的起源和进化。关于现代人起源的争论的核心是尼安德特人和解剖学上的现代人之间的祖先关系问题。这场争论集中在关于现代人起源的两种相互竞争的假设上：多区域进化（现代人从旧大陆许多地方的古代祖先进化而来）或近代非洲起源（现代人有一个单一的起源，他们从那里传播，取代了世界其他地方现存的古人类）。许多争议是关于尼安德特人是否与现代人“差异太大”，在他们的进化中是否发挥了重要作用。本研究的最终目的是通过对牙冠特征的分析来评估古代和解剖学上的现代人类样本之间的关系。为此，将使用广泛接受的牙齿形态学标准——亚利桑那州立大学牙科人类学——以及牙尖面积和牙冠形状分析，对直立人、中晚期更新世和近代人类牙齿的大量样本进行分析。结果将基于单变量和多变量统计技术以及系统发育分析的结合。据推测，如果尼安德特人在现代人类的起源中发挥了重要作用，这应该反映在他们的牙冠特征上。如果这是真的，那么分析应该证明：(1)尼安德特人的牙齿与来自同一地理区域的早期解剖学上的现代人（AMH）比来自其他地理区域的AMH更相似；(2)在现代人类牙齿模式的区域进化路径上存在差异；(3)尼安德特人缺乏大量独特的牙齿特征。(4)尼安德特人和AMH人之间的亲缘关系比其他古人类群体更密切。这项研究独特地将牙齿变异的时间和地理轴结合在一起，分析了尼安德特人和现代人之间的进化关系。在此过程中，它将对目前关于尼安德特人亲缘关系和现代人类起源的生物学和考古学假设进行独立评估。

This goal of this research is to shed light on the origin and evolution of anatomically modern humans through the first ever systematic, comparative study of Late Pleistocene hominid dental morphology from an evolutionary perspective. At the core of the debate over modern human origins is the question of the ancestral relationship between Neandertals and anatomically modern humans. This debate focuses on two competing hypotheses for modern human origins: Multiregional Evolution (modern humans evolved from archaic predecessors in many parts of the Old World) or Recent African Origin (modern humans have a single origin, from which they spread, replacing existing archaic humans in the rest of the world). Much of the controversy is over whether or not Neandertals are "too different" from modern humans to have played a significant role in their evolution. The ultimate goal of this research is to assess the relationships among archaic and anatomically modern human samples through an analysis of tooth crown characters. To this end, a large sample of Homo erectus, Middle to Late Pleistocene and Recent human teeth will be analyzed using widely accepted dental morphological standards - the Arizona State University Dental Anthropology - as well as analyses of cusp area and crown shape. Results will be based on a combination of univariate and multivariate statistical techniques and phylogenetic analyses. It is hypothesized that if Neandertals played a significant role in the origin of modern humans, this should be reflected in their tooth crown characters. If this is true, the analysis should demonstrate that (1) Neandertals are dentally more similar to early anatomically modern humans (AMH) from the same geographic region than they are to AMH from other geographic regions, (2) there are regionally distinct dental evolutionary paths toward Recent modern human dental patterns, (3) Neandertals lack a significant number dental characters that are unique to them, and (4) Neandertals and AMH more closely related to each other than either are to other archaic human groups. This study uniquely brings together temporal and geographic axes of dental variation in an analysis of the evolutionary relationship between Neandertals and modern humans. In so doing, it will provide an independent evaluation of current biological and archaeological hypotheses concerning Neandertal affinities and modern human origins.