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，而古人类化石记录是其主要数据来源。然而，在给定的时间段和地点，很难确定相对有限且零碎的古人类化石是否代表一个或多个物种。南非的南方古猿非洲化石就是这种情况。人们认为，这一化石组合的变异性代表了多个物种，但对于如何对各种化石进行分类，目前还没有达成一致。确定该组合的物种名称很重要，因为它影响对非洲人属的直接祖先的解释，从而影响我们对人属进化方式和地点的理解。通过结合系统生物学的方法和开发新的统计方法，这项研究将为定义古人类化石物种和解决古人类进化的多样性提供必要的框架。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的学生、对高中生的科学推广，以及通过 Morphosource 提供的扫描数据。化石记录中物种的识别对于理解古人类的进化和多样性至关重要。关于物种概念的文献有大量，但基于过程的定义不能轻易应用于化石物种。因此，所谓的亚基内的变异水平通常被用来描述古人类物种，但这种方法基于一个有问题的假设，即这些参数在灭绝和现存物种中具有可比性。在生物学的其他领域，已经开发出利用样本内的方差结构来检测离散物种的存在的方法。尽管关于古人类物种划分的争议不断，但这些方法尚未在人类学中得到应用。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。非洲非洲猿包含两个或多个物种的可能性对于解释古人类系统发育和人属的进化具有重要意义。这项研究的目标是对现存灵长类动物和古人类化石的物种变异进行定量建模，以便重新评估非洲猿猴组合的分类异质性。这将通过使用系统发育比较方法来估计人类变异的适当零假设模型来完成。将使用地标、半地标和基于 GIS 的方法从现存灵长类动物和古人类牙齿化石的 3D 表面收集数据。这项研究的数据将使用混合模型和矩阵相关分析提供人类变异的详细模型。