Holocene Phylochronology and Ecology of the Northern Fur Seal

北方海豹的全新世系统年代学和生态学

• 批准号: 0550827
• 负责人: Elizabeth Hadly
• 金额: $ 23.53万
• 依托单位: Stanford University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0550827&HistoricalAwards=false
• 关键词: Holocene; Phylochronology; Ecology; Northern; Fur

Historical and paleoecological data provide crucial contextual information on the behavior, ecology, and biogeography of species, particularly those that were decimated by pre-20th century harvesting. These data serve as a baseline against which to judge the significance of recent ecological shifts and to guide management decisions affecting species conservation. The objective in this research is to use genetic and isotopic tools to explore how environmental and anthropogenic factors interacted to generate ecological shifts of a top marine consumer, the northern fur seal (Callorhinus ursinus) on the northeastern Pacific coast over the past 5000 years. The most complete record of these changes is found in coastal archaeological sites, where the faunas of past terrestrial and marine ecosystems can be studied to investigate paleoecologic shifts. Furthermore, the recognition of major ecological shifts will be important for archaeologists attempting to decipher changes in human demography and resource utilization along the northeast Pacific margin throughout the Holocene. Isotopic and archaeological data show that the northern fur seal has changed its breeding and migratory behavior over the past 5000 years. Direct dating of northern fur seal bones show that the collapse of local breeding colonies was not synchronous across the Pacific margin. These data suggest that the central and northern California coastal populations experienced a prehistoric bottleneck at ~800bp. This research will directly test these results using ancient genetic data from a series of geographically distinct locations and from several time units through the Holocene. The results will be analyzed using recently developed serial coalescent models that reveal historic population connectivity and effective population size. Thus, we will be able to detect how, or if, local extinction of the southern population resulted in major effects elsewhere across the North American species range. This study will show how insights into the ecology of threatened species may be gleaned from archaeological data. This is important for species in relict populations, whose current ecology may be shaped by recent exploitation or environmental change. The species of study is presently undergoing severe population declines in the northeast Pacific Ocean, but the cause(s) for this decline are far from clear. This work will provide baseline data on the genetic diversity and population/stock structure of this species over deep and historic time, and indicate whether or not they experienced similar declines in the past in relation to anthropogenic and/or environmental perturbations. The investigators will work with conservation biologists and pinniped ecologists to make the data available to those directing management decisions. DNA sequences will be made publicly available on Genbank. The scientific impact on teaching and education is extensive. This project will contribute to the interdisciplinary education of postdoctoral scholars, graduate and undergraduate students at Stanford University. The broad appeal of ancient DNA and fossils continues to motivate the education of the general community and stimulate scientific thought in children (age 7-10) with public lab days and demonstrations.

历史和古生态数据提供了有关物种的行为，生态和生物地理学的关键上下文信息，尤其是那些被20世纪之前收获的行为。这些数据是判断最近生态转变的重要性并指导影响物种保护的管理决策的基准。 这项研究的目的是使用遗传和同位素工具来探索如何在过去5000年中在东北太平洋海岸的北部太平洋海岸北部海豹（Callorhinus ursinus）产生生态转移的环境和人为因素如何相互作用。这些变化最完整的记录是在沿海考古遗址中发现的，可以研究过去的陆地和海洋生态系统的动物群以研究古生态转移。此外，对试图破解整个全新世沿东北太平洋边缘的人口统计学和资源利用的考古学家的认识对于试图破译人口统计学和资源利用的考古学家将很重要。同位素和考古数据表明，在过去的5000年中，北部的皮草密封改变了其繁殖和迁徙行为。北部皮草密封骨的直接日期表明，在整个太平洋边缘，局部繁殖菌落的崩溃并不是同步的。这些数据表明，中部和北加州沿海人口的史前瓶颈约为800bp。这项研究将使用来自一系列地理位置上不同位置的古老遗传数据直接测试这些结果，从多个时间单元到全新世。结果将使用最近开发的连续合并模型来分析，这些模型揭示了历史悠久的人口连通性和有效的人口规模。因此，我们将能够检测到南方人口的局部灭绝是如何，或者是否会在北美物种范围内其他地方产生重大影响。这项研究将展示如何从考古数据中了解对受威胁物种的生态的见解。这对于遗物种群中的物种很重要，当前的生态学可能是由于最近的剥削或环境变化而塑造的。目前，东北太平洋的研究种群正在严重下降，但这种下降的原因远非明显。这项工作将提供有关该物种在深层和历史性时期的遗传多样性和种群/库存结构的基线数据，并指出过去与人为和/或环境扰动有关的过去是否经历了类似的下降。调查人员将与保护生物学家和固定生态学家合作，使数据可用于指导管理决策。 DNA序列将在GenBank上公开提供。对教学和教育的科学影响是广泛的。该项目将有助于斯坦福大学的博士后学者，研究生和本科生的跨学科教育。古代DNA和化石的广泛吸引力继续激励一般社区的教育，并通过公共实验室的日子和示威来激发儿童（7-10岁）的科学思想。