Collaborative Research: Paleoclimate, Paleoenvironment and Other Potential Drivers of Extinction of Mammuthus primigenius , St. Paul Island, Pribilof Islands, Alaska

该项目将提供关于白令大陆桥南缘的古气候、古环境和海平面上升对生物多样性影响的新数据，旨在更好地理解为什么猛犸象只在该地区的北极岛屿环境中存活到中全新世晚期。此外，这项研究将试图建立阿拉斯加普里比洛夫群岛圣保罗岛全新世猛犸象种群灭绝的实际时间，并将这些信息应用于检验各种提出的灭绝因果假说。圣保罗卡加洛克湖的岩心将采样摇蚊(水生无脊椎动物)、花粉、益生菌孢子、植物大型化石、木炭、古代DNA和隐语。来自摇蚊头部的氧同位素将提供一个独立的气候记录，可以通过对摇蚊组合的古生态分析来补充。研究还将测试摇蚊物种的同位素分馏，以将气候信号从地下水影响中分离出来。将从花粉、孢子和植物大型化石中重建陆地群落的变化；将使用木炭频率来记录火灾事件。对古代DNA的分析将提供传统分析方法没有发现的神秘动植物物种的数据，还可以用来识别物种的分类群。生长在动物粪便上的孢子将被用来替代猛犸象的种群数量，并记录岛上猛犸象灭绝的时间。古代DNA将作为一项重要的交叉检查，帮助解决这些孢子的特定识别问题，并提供一个独立的估计，即由于没有猛犸象DNA而灭绝的时间。从岛屿孤立到今天，将使用数字高程、水深数据、海平面曲线和地理信息系统(GIS)技术来重建岛屿的大小。Cagaloq记录的年表将通过使用14C日期和TEPhas来实现。所有数据都可以在时间上进行比较，以检验猛犸象灭绝的假设。该项目将为两名博士后、一名博士后、研究生助理和本科生提供机会。这项研究的结果将在同行评议的期刊上广泛传播。宾夕法尼亚州立大学EMS博物馆将准备一个关于该项目成果的展览，其中包括一个网络组件。此外，一个特殊的在线互动展览将允许参与者以不同的大小重建该岛，用不同的猛犸象种群繁衍，并定义不同的气候和环境因素，以观察这些因素如何影响猛犸象的灭绝。互动展览将在Neotoma数据库上提供。该小组成员将在费尔班克斯的阿拉斯加第四纪中心介绍该项目，该中心是促进阿拉斯加第四纪研究和向公众宣传的中心。

This project will provide new data on the paleoclimates, paleoenviroments and the biodiversity impacts of sea level rise on the southern edge of the Bering Land Bridge (BLB), and is intended to facilitate a better understanding of why woolly mammoths survived late into the mid-Holocene only in the environments of Arctic islands of this area. Furthermore, this research will attempt to establish the actual time of extinction of the Holocene mammoth population on St. Paul Island, Pribilof Islands, Alaska, and apply this information to test various proposed causal hypotheses for the extinction.Cores from Cagaloq Lake, St. Paul, will be sampled for chironomids (aquatic invertebrates), pollen, coprophilous fungi spores, plant macrofossils, charcoal, ancient DNA and cryptotephras. Oxygen isotopes from the heads of chironomids will provide an independent climate record that can be supplemented by paleoecological analyses of the chironomid assemblages. Studies will also test chironomid species for isotope fractionation to disentangle climate signals from ground water effects. Terrestrial community changes will be reconstructed from pollen, spores and plant macrofossils; and charcoal frequency will be used to document fire events. Analysis of ancient DNA will provide data on cryptic plant and animal species that have not been detected by traditional methods of analysis, and can also be used to identify taxa to species.Spores that grow on animal dung will be used as proxies for the mammoth population size and to document the time of mammoth extinction on the island. Ancient DNA will serve as an important cross-check by helping to resolve specific identifications of these spores as well as providing an independent estimate the time of extinction by the absence of mammoth DNA.Digital elevations, bathymetric data, sea level curves, and Geographic Information System (GIS) technology will be used to reconstruct island size from the time of its isolation until today. A highly constrained chronology of the Cagaloq record will be achieved by using 14 C dates and tephras. All data can be compared temporally in order to test hypotheses for mammoth extinction. This project will provide opportunities for two PhD students, a postdoctoral fellow, graduate student assistant and undergraduate student. Results of the study will be disseminated widely in peer-reviewed journals. An exhibit on the results of the project will be prepared by the EMS Museum at Penn State University with a web component. In addition, a special on-line, interactive exhibit will allow participants to reconstruct the island at various sizes, populate it with differing mammoth populations and define different climate and environmental factors to observe how each of these components affects mammoth extinction. The interactive exhibit will be available on the Neotoma database. Members of the group will make presentations on the project at the Alaska Quaternary Center in Fairbanks, which serves as a hub for promoting Alaska Quaternary research and outreach to the public.