Doctoral Dissertation Improvement: Dental Microwear of Pliocene Bovids from East African Hominin Sites: Implications for Paleoenvironmental Dynamics and Human Evolution

博士论文改进：东非古人类遗址上新世牛科动物的牙齿微磨损：对古环境动力学和人类进化的影响

• 批准号: 0925822
• 负责人: Peter Ungar
• 金额: $ 1.5万
• 依托单位: University of Arkansas
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0925822&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Improvement; Dental; Microwear

Many researchers have suggested that Pliocene climate change was a motive force for human evolution. The basic idea was that a shift toward drier, more open settings led to adaptations for bipedality and the consumption of savanna resources, including large grazing mammals. However, more recent paleoenvironmental reconstructions suggest that Pliocene hominins occupied more variable or mosaic habitats including both open and closed settings. While many techniques have been used to refine our understanding of the paleoenvironments of eastern Africa, these have not led to consensus reconstructions. This project will test competing hypotheses for the paleoenvironments of four sites associated with Australopithecus anamensis and A. afarensis by bringing a new, independent dataset for the inference of diet and by extension, habitats, of actual individuals in the days preceding their death. This study uses dental microwear texture analysis to reconstruct ratios of graze to browse in the diet, and therefore ecological contexts, of fossil bovids from Kanapoi (8 genera), Allia Bay (7 genera), Laetoli (8 genera) and Hadar (9 genera). This project will reconstruct the paleoenvironments of these four important early hominin sites and how ecological settings may have changed over the temporal spans of the hominins that lived there. Intellectual Merit: A large database of microwear textures for both extant and fossil bovids will be generated, and will provide a substantial comparative collection for future research. It will also serve as an important test of taxonomic uniformitarianism, which is often assumed in the use of faunal assemblages as paleoenvironmental proxies. In addition, since evolutionary changes in A. anamensis and A. afarensis are widely considered to be adaptations to shifting paleohabitats, the improved reconstructions resulting from this study will have important implications for understanding the relationship between environmental change and human evolution in eastern Africa during the Pliocene. The broader impacts of this study include establishing a doctoral dissertation research program for a female graduate student from an underserved, EPSCoR state and provide a research assistantship to an undergraduate through the University of Arkansas Honors College-Environmental Dynamics Research Mentoring Experience for Students (HERMES) program. It will provide both students with training in data collection techniques and research methods.

许多研究人员认为，上新世气候变化是人类进化的动力。基本思想是，向更干燥，更开放的环境转变导致了对双层的适应和消费稀树草原资源，包括大量放牧的哺乳动物。但是，最近的古环境重建表明，上新世植物占据了更可变或镶嵌栖息地，包括开放和封闭环境。尽管许多技术已被用来完善我们对东非古环境的理解，但这些技术并未导致共识重建。该项目将通过在其死亡之前引入一个新的独立数据集来检验与Australopithecus anamensis和A. farensis相关的四个地点的古环境的竞争假设。这项研究使用牙科微生纹理分析来重建放牧比在饮食中浏览的比例，从而在饮食中浏览来自Kanapoi（8属），Allia Bay（7属），Laetoli（8属）（8属）和Hadar（9属）的化石牛的化石牛。该项目将重建这四个重要的早期人类现场的古环境，以及生态环境如何在居住在那里的人类的暂时性上发生变化。 知识分子优点：将生成一个大型的微型纹理数据库，用于现存和化石牛的，并将为将来的研究提供大量的比较收集。它还将作为分类统一主义的重要检验，通常在使用动物组合作为古环境代理时假设。此外，由于广泛认为阿纳不明和杂志的进化变化被认为是适应古居民的适应，因此这项研究引起的改进的重建将对理解上新世期间东非的环境变化与人类进化之间的关系具有重要意义。 这项研究的更广泛影响包括为来自服务不足的EPSCOR州的女性研究生建立博士学位论文研究计划，并通过阿肯色大学荣誉学院 - 环境动态研究指导学生（HERMES）计划为本科生提供研究助学金。它将为学生提供数据收集技术和研究方法的培训。