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.

历史和古生态学数据提供了有关物种行为、生态和地理的重要背景信息，特别是那些在世纪前被大量砍伐的物种。这些数据作为一个基准，以判断最近的生态变化的意义，并指导管理决策影响物种保护。 在这项研究的目的是使用遗传和同位素工具，以探讨如何环境和人为因素相互作用，以产生生态变化的顶级海洋消费者，北方海狗（Callorhinus ursinus）在东北太平洋沿岸在过去的5000年。这些变化的最完整的记录是在沿海考古遗址中发现的，在那里可以研究过去陆地和海洋生态系统的动物群，以调查古生态变化。此外，认识到主要的生态变化将是重要的考古学家试图破译的变化，人类人口和资源利用沿着整个全新世的东北太平洋边缘。同位素和考古资料显示，在过去的5000年里，北方海狗的繁殖和迁徙行为发生了变化。对北方海狗骨骼的直接测年表明，当地繁殖群体的崩溃并不是在太平洋边缘同步发生的。这些数据表明，中部和北方加州沿海人口经历了史前瓶颈约800 bp。这项研究将直接测试这些结果使用古代遗传数据从一系列不同的地理位置和从几个时间单位通过全新世。结果将使用最近开发的系列聚结模型，揭示历史人口连接和有效人口规模进行分析。因此，我们将能够检测南部种群的局部灭绝如何或是否对整个北美物种范围的其他地方产生了重大影响。这项研究将展示如何从考古数据中收集到对受威胁物种生态学的见解。这对孑遗种群中的物种很重要，它们目前的生态可能是由最近的开发或环境变化所塑造的。该物种的研究目前正在经历严重的人口下降在东北太平洋，但这种下降的原因还远不清楚。这项工作将提供关于这一物种的遗传多样性和种群/种群结构的长期和历史基线数据，并表明它们在过去是否因人为和/或环境扰动而经历过类似的下降。研究人员将与保护生物学家和鳍足动物生态学家合作，使这些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着普通社区的教育，并通过公共实验室日和演示激发儿童（7-10岁）的科学思想。