Quantifying the Duration and Impact of Human-Megafauna Overlap in Australia

在NSF考古计划的支持下，Gifford米勒教授和澳大利亚合作者将在澳大利亚西北部进行实地考察，以确定两种巨型鸟类蛋壳碎片周围的人类背景，灭绝的巨型动物鸟类Genyornis和现存的澳大利亚鸸鹋（Dromaius）。 西澳大利亚州的野外活动提供了一个独特的机会，可以牢固地建立人类与灭绝的巨型动物之间的相互作用，并量化人类与巨型动物重叠的持续时间。 米勒的团队之前的野外工作记录了早期人类使用Genyornis蛋作为食物来源，烹饪，后来在火中燃烧一些蛋壳。 这是人类对澳大利亚巨型动物进行捕食的第一个可靠证据。澳大利亚考古学家将在早期人类占领遗址中积累丰富的经验，并将陪同该团队推导出烧焦的蛋壳与人类活动之间的可靠关系。该项目的一个中心目标是应用四种独立的测年方法来确定人类与巨型动物重叠的时间;一个由美国和澳大利亚测年专家组成的团队已被召集来实现这一目标。 一项重大创新是开发了一种测量蛋壳中铀同位素痕量水平的协议，利用质谱法的最新发展，大大提高了检测水平。 结合这些测量，蛋壳的矿物和有机成分中含有的氧、碳和氮的稳定同位素可以表征气候和鸟类饮食的状况。 通过分析Dromaius蛋壳，从人类殖民澳大利亚之前很久就生活的鸟类直到今天，它将有可能独立评估气候变化和可能发生的任何饮食变化。 这些数据集可以将与气候变化有关的影响与人类殖民化造成的影响区分开来。 将灭绝的Genyornis与共存的Dromaius的饮食喂养策略进行比较，将有助于理解为什么一种巨型鸟类灭绝，而另一种适应了相同的压力并仍然存在。澳大利亚的殖民化是世界史前史更大故事中的一个重要因素。 更一般地说，这是至关重要的，以了解人类殖民地的足迹从未被人类访问过的景观，以及人类对外来环境的适应性。这项研究有可能解决长期存在的争议，无论是人类的扩散是沿着海岸到澳大利亚南部，然后内陆，或通过大陆内部。从创始人口的分散模式提供了适应和社会结构的限制。 由于缺乏可靠的年代测定工具，在早期人类历史上确定这些事件的年代一直受到阻碍。 拟议研究的一个关键方面是测试和改进鸟类蛋壳的U/Th测年。 如果成功，这种强大的测年工具的加入不仅将重振澳大利亚早期人类遗址的研究，而且还将对非洲和欧亚大陆的考古研究产生深远的影响，鸵鸟蛋壳是许多考古遗址的常见元素，超出了14 C测年的范围。 这项研究抓住了公众的想象力。米勒已经为相关的电视和流行媒体外联活动提供了便利，并将继续这样做。

With support from NSF's Archaeology Program, Prof Gifford Miller and Australian collaborators will conduct fieldwork in NW Australia to define the human context surrounding eggshell fragments from two giant bird species, the extinct megafaunal bird Genyornis, and the extant Australian emu (Dromaius). The Western Australia field campaign offers a unique opportunity to firmly establish the interactions between humans and extinct giant animals, and to quantify the duration of human-megafauna overlap. Previous fieldwork by Miller's team documented early human use of Genyornis eggs as a food source, cooking, and later burning some of the eggshells in their fires. This is the first secure evidence of human predation on the Australian megafauna. Australian archaeologists experienced in early human occupation sites will accompany the team to derive secure relations between the burnt eggshell and human activity.A central goal of this project is to apply four independent dating methods to firmly define the duration of human-megafauna overlap; a team of US and Australian dating experts has been assembled to accomplish this goal. A major innovation is development of a protocol to measure trace levels of uranium isotopes in eggshells, capitalizing on recent developments in mass spectrometry that have greatly improved detection levels. In conjunction with these measurements, the stable isotopes of oxygen, carbon and nitrogen contained in the mineral and organic constituents of the eggshells allow characterization of the status of climate and the birds' diet. By analyzing Dromaius eggshells from birds living long before human colonization of Australia up through the present day it will be possible to evaluate independently changes in both climate and any dietary shifts that may have occurred. Such datasets allow the separation of impacts related to climate change from those due to human colonization. Comparing the dietary feeding strategies of the extinct Genyornis with co-existing Dromaius will help understand why one giant bird became extinct whereas the other adapted to the same stressors and remains extant.The colonization of Australia is an important element in the larger story of World prehistory. More generally, it is essential to understanding the footprint of human colonization of landscapes never before visited by humans, and the adaptability of humans to alien environments. This research has the potential to resolve long-standing disputes whether human dispersal was along the coasts to southern Australia and then inland, or through the continental interior. The dispersal pattern from a founding population provides constraints on both adaptation and social structures. Dating these events in early human history has been hampered by a lack of reliable dating tools. A key aspect of the proposed research is to test and refine U/Th dating of avian eggshell. If successful, the addition of this powerful dating tool will reinvigorate not only the study of early human sites in Australia, but it also will have profound effects in archaeological studies across Africa and Eurasia where ostrich eggshells are common elements of many archaeological sites beyond the range of 14C dating. This research captures the imagination of the general public. Miller has already facilitated related TV and popular media outreach activities, and will continue to do so.