Doctoral Dissertation Research: Modeling hominin variability in Australopithecus africanus

博士论文研究：非洲南方古猿的人类变异建模

• 批准号: 1613401
• 负责人: Frederick Grine
• 金额: $ 2.19万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-15 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1613401&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Modeling; hominin

One of the fundamental goals of anthropological research is to understand humanity's biological origins and evolution, for which the hominin fossil record is a primary source of data. However, it is difficult to determine, for a given time period and location, whether the relatively limited and fragmentary hominin fossils represent one or multiple species. Such is the case for South African fossils attributed to the species Australopithecus africanus. The variability in this assemblage of fossils has been proposed to represent more than one species, but there is little agreement about how to sort the various fossils. Determining species designations for this assemblage is important because it affects interpretations of A. africanus as a direct ancestor of our own genus Homo and therefore our understanding of how and where the genus Homo evolved. By incorporating methods from systematic biology and developing new statistical methods, this research will provide a necessary framework to define hominin fossil species and address diversity in hominin evolution. This project will also support training and mentoring of students, including from groups underrepresented in STEM fields, science outreach to high school students, and scan data that will be made available through Morphosource. The recognition of species in the fossil record is of critical importance to understanding hominin evolution and diversity. A vast literature exists on species concepts, but process-based definitions cannot be easily applied to fossil species. Accordingly, levels of variation within purported hypodigms have typically been used to delineate hominin species, but such approaches rest on the problematic assumption that these parameters are comparable in extinct and extant species. Elsewhere in biology, methods have been developed that use the structure of variance within a sample to detect the presence of discrete species. Despite continued controversy over hominin species delineation, these methods have yet to be employed in anthropology. Australopithecus africanus exemplifies this problem. Resolving its alpha taxonomy is critically important to interpreting human evolution, but it remains a contentious issue. The possibility that A. africanus subsumes two or more species has significant implications for the interpretation of the hominin phylogeny and the evolution of the genus Homo. The goal of this research is to quantitatively model species variation in extant primates and fossil hominins in order to re-evaluate the taxonomic heterogeneity of the A. africanus assemblage. This will be accomplished by using phylogenetic comparative methods to estimate an appropriate null hypothesis model of hominin variability. Data will be collected from 3D surfaces of extant primate and fossil hominin teeth using landmarks, semi-landmarks, and GIS-based approaches. The data from this study will provide a detailed model of hominin variability using both mixture models and matrix correlation analyses.

人类学研究的基本目标之一是了解人类的生物起源和进化，人类化石记录是其主要数据来源。然而，在一个特定的时间段和地点，很难确定相对有限和零碎的人类化石是代表一个还是多个物种。南非南方古猿（Australopithecus africanus）的化石就是如此。这一化石组合的变异性被认为代表了不止一个物种，但关于如何对各种化石进行分类，人们几乎没有达成一致。确定这一组合的物种名称是重要的，因为它影响到A。africanus作为我们自己的人属的直接祖先，因此我们对人属如何以及在哪里进化的理解。通过整合系统生物学的方法和开发新的统计方法，这项研究将提供一个必要的框架来定义人类化石物种和解决人类进化的多样性。该项目还将支持对学生的培训和指导，包括来自STEM领域代表性不足的群体，对高中生的科学宣传，以及通过Morphosource提供的扫描数据。化石记录中的物种识别对于理解人类进化和多样性至关重要。关于物种的概念有大量的文献，但基于过程的定义不能轻易地应用于化石物种。因此，通常使用声称的亚基内的变异水平来描绘人类物种，但这种方法依赖于有问题的假设，即这些参数在灭绝和现存物种中是可比的。在生物学的其他领域，已经开发出了使用样本中的方差结构来检测离散物种的存在的方法。尽管对人类物种的划分一直存在争议，但这些方法尚未在人类学中使用。非洲南方古猿就是这个问题的例证。解决其阿尔法分类对于解释人类进化至关重要，但它仍然是一个有争议的问题。A. africanus包含两个或两个以上的物种对于解释人类的起源和人属的进化具有重要意义。本研究的目的是定量模拟现存灵长类和化石人类的物种变异，以重新评估A。africanus组合这将通过使用系统发育比较方法来估计一个适当的零假设模型的人的变异性。数据将收集从现存的灵长类动物和化石人类牙齿的3D表面使用地标，半地标，和基于GIS的方法。这项研究的数据将提供一个详细的模型，使用混合模型和矩阵相关分析的人的变异性。