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

人类(祖先人类)饮食中吃肉的进化是关于人属的出现、现代身体计划的发展、寿命的延长以及人从非洲扩展到欧亚大陆和更远地区的假说的核心。季节性的资源波动可以对这样的适应性发展产生深远的影响，事实上，正是在早更新世(2.588-78.1万年前)干旱和季节性加剧的时期，出现了人类食肉的最早证据。然而，目前对原始人觅食的季节性动态知之甚少。这项研究通过考察坦桑尼亚奥杜瓦伊峡谷觅食肉类的时间，及时洞察了早期人类在气候变化和多变性延长时期的成功策略。虽然肉类有可能增加季节性或每年的能量预算，但它也使原始人与捕食者和食腐动物竞争。奥杜瓦伊屠宰的技术和行为证据表明，尽管存在危险，但在稀树草原扩张和森林萎缩的背景下，肉类是一种越来越有价值的资源。除了讲述原始人进化的这一关键时期，奥杜瓦伊非常适合这个项目，因为它是190万至120万年前研究最深入的地方之一，也是关于原始人肉类觅食和景观使用的辩论的中心。那里的研究将有助于国际和地方合作的悠久传统，为未来的古人类学家和保护者提供宝贵的持续培训，他们将保护我们的文化遗产。该项目还将进一步培训威斯康星大学的研究生Alia Gurtov，并将为她的博士论文提供数据。通过研究奥杜瓦伊人类觅食的时间，这项研究可以阐明在降雨量较少和资源相对稀缺的时期，肉类作为资源的重要性，以及提高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)对牛化石猎物进行分析。DMTA是一种非破坏性技术，它使用尺度敏感的分形分析来检查反映有机体前几周或前几天饮食断裂特性的微观磨损。初步研究表明，DMTA能够区分哈扎族狩猎采集者在雨季和旱季狩猎的黑斑羚(Aepyceros Melampus)的组合。作为一种食草动物，黑斑羚是Olduvai几个常见猎物物种的合适现代类似物。虽然DMTA不能识别个体的死亡季节，但它可以相对地使用。人为组合Flk Zinj与食肉动物生成的Flk North组合是准同时代的，位于200米之外。这项研究将使用现代黑斑羚的模拟来确定哪个季节在每个地方表现得最好，并比较结果，看看人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。这项研究将开始确定早期更新世人的肉类获取是否随季节变化，以及该策略是否邀请或避免与食肉动物对抗，从而有助于我们对更新世人觅食适应的了解。

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.