Doctoral Dissertation Improvement Award: Determining Season Of Death By Dental Microwear Analysis

人类祖先饮食中食肉的进化是关于人属出现、现代体型发展、寿命延长以及人类从非洲向欧亚大陆及其他地区扩张的假说的核心。季节性的资源波动会对诸如此类的适应性发展产生深远的影响，事实上，正是在早更新世（258.8 - 78.1万年前[Ma]）干旱和季节性增加的时期，出现了人类食肉的最早证据。然而，人们对人类觅食的季节性动态知之甚少。这项研究提供了一个及时的洞察早期人属的成功策略，在一个长期的气候变化和变化，通过研究肉类觅食的时间在奥杜威峡谷，坦桑尼亚。虽然肉类有可能增加季节性或年度的能量预算，但它也使人类与食肉动物和食腐动物竞争。奥杜威屠宰业的技术和行为证据表明，尽管存在危险，但在热带稀树草原不断扩大、森林不断减少的背景下，肉类是一种越来越有价值的资源。除了涵盖人类进化的这一关键时期外，奥杜威非常适合该项目，因为它是190万至120万年前研究最好的地点之一，并且是关于人类肉类觅食和景观使用的争论的中心。那里的研究将有助于国际和本地合作的悠久传统，为未来保护我们文化遗产的古人类学家和保护主义者提供宝贵的持续培训。该项目还将进一步培训威斯康星州大学的研究生阿利亚古尔托夫，并为她的博士论文提供数据。通过研究古人类在奥杜威觅食的时间，这项研究可以阐明在低降水和相对资源稀缺的时代，肉类作为一种资源的重要性，以及提升古人类在新的营养水平上竞争的策略。它将使用牙齿微磨损纹理分析（DMTA）对化石牛科猎物。DMTA是一种非破坏性技术，使用尺度敏感分形分析来检查反映生物体饮食在前几周或前几天的断裂特性的微观磨损。试点研究表明，DMTA能够区分哈扎狩猎采集者在雨季和旱季狩猎的黑斑羚（Aepyceros melampus）。作为一种食草动物，黑斑羚是奥杜威几种常见猎物的适当的现代类似物。虽然DMTA不能确定个体的死亡季节，但可以进行比较。人类活动的组合FLK Zinj与食肉动物产生的组合FLK北，位于200米远的准同期。这项研究将使用现代的黑斑羚模拟来确定哪个季节在每个地方最具代表性，并比较结果，看看人类和食肉动物是否在一年中的相同时间在相同的环境中活动。 这项研究将开始，以确定是否早更新世人类肉类收购季节性变化，如果该战略邀请或避免与食肉动物的对抗，从而有助于我们的知识更新世人类觅食的适应。

The evolution of meat eating in the hominin (ancestral human) diet is central to hypotheses about the emergence of the genus Homo, the development of the modern body plan, the elongation of lifespan, and the hominin expansion from Africa into Eurasia and beyond. Seasonal resource fluctuation can have a profound effect on adaptive developments such as these, and indeed, it is during the increased aridity and seasonality of the Early Pleistocene (2.588 - 0.781 million years ago [Ma]) that the earliest evidence for hominin meat-eating appears. However, little is known about the seasonal dynamics of hominin foraging at this time. This study provides a timely insight into the successful strategies of early Homo during an extended period of climate change and variability by examining the timing of meat foraging at Olduvai Gorge, Tanzania. Though meat had the potential to increase energy budgets seasonally or annually, it also placed hominins in competition with both predators and scavengers. Technological and behavioral evidence for butchery at Olduvai suggests that despite the dangers, meat was an increasingly valuable resource in the context of expanding savannas and receding forests. In addition to covering this critical time in hominin evolution, Olduvai is well-suited for the project because it is among the best-studied localities dating to 1.9 - 1.2 million years ago, and is at the center of debates about hominin meat foraging and landscape use. Research there will contribute to the long tradition of international and local collaboration, providing valuable ongoing training to the future paleoanthropologists and conservationists who will safeguard our cultural heritage. The project will also further the training of Alia Gurtov, a graduate student at the University of Wisconsin and will provide data for her doctoral dissertation. By examining the timing of hominin foraging at Olduvai, this research can elucidate the significance of meat as a resource in times of low precipitation and relative resource scarcity, and the strategies that elevated hominins to compete at a new trophic level. It will do so using dental microwear texture analysis (DMTA) on fossil bovid prey. DMTA is a non-destructive technique that uses scale sensitive fractal analysis to examine microscopic abrasions reflecting the fracture properties of an organism's diet in the previous weeks or days. Pilot research has demonstrated that DMTA is capable of distinguishing between assemblages of impala (Aepyceros melampus) hunted by Hadza hunter-gatherers in the wet and dry seasons. As a browser-grazer, impala are an appropriate modern analog for several common prey species at Olduvai. Though DMTA cannot identify the season of death for individuals, it can be used comparatively. The anthropogenic assemblage FLK Zinj is penecontemporaneous with the carnivore-generated assemblage of FLK North, located 200 meters away. This study will use the modern impala analog to ascertain which season is best represented at each locality and compare the results to see if hominins and carnivores were operating during the same times of the year in the same environments. This research will begin to determine if Early Pleistocene hominin meat-acquisition varied seasonally, and if the strategy invited or avoided confrontation with carnivores, thereby contributing to our knowledge of Pleistocene hominin foraging adaptations.