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

合作研究：古气候、古环境和其他猛犸象灭绝的潜在驱动因素，圣保罗岛，普里比洛夫群岛，阿拉斯加

• 批准号: 1203990
• 负责人: Beth Shapiro
• 金额: $ 28.78万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-02-01 至 2017-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1203990&HistoricalAwards=false
• 关键词: Collaborative; Research; Paleoclimate; Paleoenvironment; Other

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.

该项目将提供有关白令陆桥 (BLB) 南缘古气候、古环境和海平面上升对生物多样性影响的新数据，旨在帮助更好地了解猛犸象为何能存活到中世纪晚期。全新世仅存在于该地区北极岛屿的环境中。此外，这项研究将尝试确定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，并应用这些信息来测试各种提出的灭绝因果假设。保罗，将对摇蚊（水生无脊椎动物）、花粉、粪菌孢子、植物化石进行采样，木炭、古代 DNA 和隐石。摇蚊头部的氧同位素将提供独立的气候记录，并可以通过对摇蚊组合的古生态分析进行补充。研究还将测试摇蚊物种的同位素分馏，以将气候信号与地下水影响分开。陆地群落变化将由花粉、孢子和植物大化石重建；木炭频率将用于记录火灾事件。对古代 DNA 的分析将提供传统分析方法未检测到的神秘植物和动物物种的数据，也可用于识别物种的分类群。在动物粪便上生长的孢子将用作猛犸象种群的代表大小并记录岛上猛犸象灭绝的时间。古代 DNA 将作为重要的交叉检查，帮助解决这些孢子的具体鉴定问题，并提供猛犸象 DNA 缺失导致的灭绝时间的独立估计。数字高程、测深数据、海平面曲线和地理信息系统（GIS）技术将用于重建从孤立时期直到今天的岛屿大小。通过使用 14 C 日期和火山灰，可以实现高度受限的 Cagaloq 记录年表。所有数据都可以进行时间比较，以检验猛犸象灭绝的假设。该项目将为两名博士生、一名博士后、研究生助理和本科生提供机会。研究结果将在同行评审期刊上广泛传播。宾夕法尼亚州立大学的 EMS 博物馆将通过网络组件准备一个关于该项目成果的展览。此外，一个特殊的在线互动展览将允许参与者重建不同大小的岛屿，在岛上填充不同的猛犸象种群，并定义不同的气候和环境因素，以观察这些组成部分如何影响猛犸象的灭绝。互动展览将在 Neotoma 数据库中提供。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推广的中心。