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.

许多研究者认为上新世的气候变化是人类进化的动力。其基本思想是，向更干燥、更开放的环境转变，导致了对两足动物的适应和对稀树草原资源的消耗，包括大型放牧哺乳动物。然而，最近的古环境重建表明，上新世人类占据了更多的变量或马赛克栖息地，包括开放和封闭的设置。虽然许多技术已被用来完善我们的理解非洲东部的古环境，这些都没有导致共识重建。这个项目将测试与南方古猿anamensis和A。通过带来一个新的，独立的数据集，用于推断饮食，并通过扩展，栖息地，在他们死亡前的几天，实际的个人。本研究使用牙齿微磨损纹理分析重建比例的放牧浏览饮食，因此生态环境，化石牛科动物Kanapoi（8属），阿利亚湾（7属），Laetoli（8属）和哈达尔（9属）。该项目将重建这四个重要的早期人类遗址的古环境，以及生态环境如何在生活在那里的人类的时间跨度上发生变化。 智力优势：将产生一个大型的现存和化石牛科动物的微磨损纹理数据库，并将为未来的研究提供大量的比较收集。它也将作为一个重要的测试分类均匀，这是经常假设在使用动物群组合作为古环境代理。此外，由于A. anamensis和A. afarensis被广泛认为是适应不断变化的古栖息地，从这项研究中得到的改进重建将有重要的意义，了解上新世期间非洲东部环境变化和人类进化之间的关系。 这项研究的更广泛的影响，包括建立一个女研究生的博士论文研究计划，从一个服务不足，EPSCoR状态，并通过阿肯色州荣誉学院环境动力学研究指导经验的学生（爱马仕）计划的大学提供研究助学金给本科生。它将为学生提供数据收集技术和研究方法的培训。