Doctoral Dissertation Research Award: use of Eggshell Isotopes for Mobility

这篇博士论文的研究将通过分析一个传统的集团如何利用鸵鸟蛋壳的同位素分析在边缘环境中管理资源采购来研究人类的流动性。了解人类群体在世界各地移动时如何适应行为是了解人类如何成为地球上人口最多的大型哺乳动物的核心组成部分。人们适应环境多样性和气候变化的一种方式是调整他们的流动模式、资源集水区和贸易网络。该项目将利用鸵鸟蛋壳中的稳定同位素来重建古气候，同时利用锶同位素分析来辨别流动模式并确定可能的贸易网络，评估流动如何应对气候变化。鸵鸟蛋壳是一种经常被忽视的资源，在许多考古学沉积物中丰富，表明这些鸡蛋作为生存资源的重要性。由于鸵鸟蛋壳在许多考古遗址中很常见，因此建立标准化的方法来收集干净的样品并在感兴趣的景观上制作生物可利用的锶地图，将使研究人员能够生成易于比较的数据，并作为未来项目的基线。复杂的人类行为与鸵鸟蛋壳有关，它们被用于珠子制作、象征性雕刻以及在水稀少的环境中携带或储存水的容器。考古记录为欧洲殖民化前后现代人类起源和狩猎采集者和牧民生活方式的调查提供了重要信息，并提供了广泛的生态系统，以研究早期人类行为并探索过去的人类群体如何谋生。 为了实现这个项目的目标，加州大学的博士候选人戴维斯将设计一个说明区域生物锶的地图。这张地图将是一个有价值的工具，作为本项目以及其他研究人员在各种学科的基线。麦克尼尔将通过比较考古鸵鸟蛋壳中的锶值与地图来评估蛋壳的可能来源，从而调查流动性和资源集水区变量，从而了解群体愿意旅行或贸易多远以获得这种有价值的多功能资源。研究人员将开发和改进从蛋壳中提取未受污染的方解石的方法，以进行锶同位素分析，以促进空间评估。这种未受污染的贝壳材料沿着来自贝壳有机成分的胶原蛋白，然后将被采样用于稳定同位素分析，以促进研究区域的古气候重建。对多条同位素证据的分析增强了这些分析的解释力，有助于理解人类的流动性和人类利用的食物网，特别是在过去环境变化的背景下。从鸵鸟蛋壳中收集的丰富数据将为研究人员提供另一种资源，用于理解人类过去的使命。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

This doctoral dissertation research will investigate human mobility by analyzing how a traditional group managed resource procurement in a marginal environment using isotopic analyses of ostrich eggshell. Understanding how groups of humans behaviorally adapted as they moved across the world is a core component to understanding how humans came to be the most populous large mammal on earth. One way people adapted to a diversity of environments and changing climates was by adjusting their mobility patterns, resource catchment areas, and trade networks. This project will utilize the stable isotopes in ostrich eggshell to create paleoclimatic reconstructions while employing strontium isotope analysis to discern mobility patterns and identify possible trade networks, assessing how movement responded to climatic change. Ostrich eggshell is an often-overlooked resource that is abundant in many archaeological deposits, signaling the importance of these eggs as a subsistence resource. Because ostrich eggshell is common in many archaeological sites, establishing standardized methods of collecting clean samples and of producing maps of bioavailable strontium on the landscapes of interest will allow researchers the benefit of generating data that can be easily compared and serve as a baseline for future projects. Complex human behavior is linked to ostrich eggshell through use in bead making, symbolic engravings, and containers that carry or cache water in environments where water is sparse. The archaeological record significantly informs investigations into modern human origins and hunter-gatherer and pastoralist lifeways before and after European colonization and provides a wide range of ecosystems from which to study early human behavior and to explore how past human groups made their living. To achieve the goals of this project adoctoral candidate at the University of California Davis will engineer the creation of a map illustrating regional biogenic strontium. This map will be a valuable tool as a baseline to this project as well as to other researchers in a variety of disciplines. McNeill will investigate mobility and resource catchment variables by comparing strontium values in archaeological ostrich eggshell to the map to assess the likely source of the eggshell, allowing one to discern how far groups were willing to travel or trade to obtain this valuable and versatile resource. The researchers will develop and refine methods for extracting uncontaminated calcite from the eggshell to be processed for strontium isotope analysis to facilitate the spatial assessment. This uncontaminated shell material along with collagen from the organic component of the shell will then be sampled for stable isotope analysis to facilitate the paleoclimatic reconstruction of the study region. Incorporating multiple lines of isotopic evidence enhances the interpretive power of these analyses for understanding human mobility and the food webs humans exploited, especially in the context of past environmental variability. The richness of data that can be gleaned from ostrich eggshells will provide researchers with another resource to employ in the mission to understand the human past.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.