Collaborative Research: Land Bridges, Ice-Free Corridors, and Biome Shifts: Impacts on the Evolution and Extinction of Horses in Ice-Age Beringia

合作研究：陆桥、无冰走廊和生物群落变化：对冰河时代白令陆桥马的进化和灭绝的影响

• 批准号: 1417036
• 负责人: Beth Shapiro
• 金额: $ 42.3万
• 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: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1417036&HistoricalAwards=false
• 关键词: Collaborative; Research; Land; Bridges; Ice

Title: Land Bridges, Ice-Free Corridors, and Biome Shifts: Impacts on the Evolution and Extinction of Horses in Ice-Age BeringiaThis study asks: How important was connectivity among populations of large arctic mammal species for maintaining genetic diversity, influencing evolutionary change, and mitigating extinction risk? What types of barriers affected this connectivity, and how permeable were these barriers to gene flow? The PIs will study how caballine horses, that inhabited ice-age Beringia (the biogeographic connector between Asia and North America), were affected by changes involving three different biogeographic barriers/corridors (1. the Bering Strait/Bering Land Bridge, which controlled dispersal and gene flow between Eurasia and Alaska; 2. the Ice-Free Corridor, which controlled gene flow between the Yukon and the Lower 48 States; and 3. biome shifts that periodically disrupted the spatial continuity of the Mammoth-Steppe, the unique ecosystem that stretched from France to the Yukon during the ice ages) during the last 30,000 years of the ice age. This study will evaluate the effects that each of these putative barriers to gene flow had on the abundance, distribution, and evolutionary trajectories of ice-age horses in the Arctic using new paleogenomic and paleoenvironmental data. The results will provide new insights into the roles played by environmental change and population fragmentation in determining extinction risk, and help predict how ongoing environmental changes will affect arctic ecosystems. This project will lead to advances in the rapidly developing field of paleogenetics and further the brand-new discipline of paleogenomic ecology. The Broader Impacts plan focuses on: a) research and professional development opportunities for graduate students, b) new training opportunities for undergraduate students who aspire to become STEM high school teachers, c) outreach to Native communities in rural Alaska, and d) outreach to K-12 students in Fairbanks, AK. At the end of each summer, the pre-service teachers, graduate students, and PIs will produce an inquiry activity module for grades 9-12 to be shared with local schools. Finally, the PIs will engage in both professional and public discourse, and use the results in media productions.This is an interdisciplinary study combining cutting-edge paleogenomic techniques with newly synthesized paleoecological data to infer how arctic species were affected by past changes in climate, vegetation, and population connectivity. It builds on extensive previous work by the investigators, including hundreds of previously 14C-dated horse bones from permafrost that comprise a globally unique archive of ancient DNA.

职务名称：陆桥、无冰走廊和生物群落的变化：对冰河时代贝林吉马的进化和灭绝的影响这项研究问：大型北极哺乳动物种群之间的连通性对维持遗传多样性、影响进化变化和减轻灭绝风险有多重要？什么类型的障碍影响了这种连通性，这些障碍对基因流动的渗透性如何？PI将研究如何caballine马，居住在冰河时代的白令加（亚洲和北美之间的地理连接器），受到影响的变化，涉及三个不同的地理障碍/走廊（1。白令海峡/白令陆桥，控制了欧亚大陆和阿拉斯加之间的扩散和基因流动; 2.无冰走廊，控制着育空地区和48个州之间的基因流动;生物群落的变化周期性地破坏了猛犸象草原的空间连续性，猛犸象草原是冰河时期从法国延伸到育空地区的独特生态系统）。本研究将评估这些假定的基因流障碍的影响，在北极使用新的古基因组学和古环境数据的丰度，分布和冰河时期的马的进化轨迹。研究结果将为环境变化和人口碎片化在确定灭绝风险方面所发挥的作用提供新的见解，并有助于预测持续的环境变化将如何影响北极生态系统。该项目将推动快速发展的古遗传学领域的发展，并进一步发展古基因组生态学这一全新的学科。“更广泛的影响”计划的重点是：a）研究生的研究和专业发展机会，B）渴望成为STEM高中教师的本科生的新培训机会，c）阿拉斯加农村地区的土著社区，d）AK州费尔班克斯的K-12学生。在每个夏天结束时，职前教师，研究生和PI将产生一个调查活动模块9-12年级与当地学校分享。最后，PI将参与专业和公共话语，并将结果用于媒体制作。这是一项跨学科的研究，将尖端的古基因组学技术与新合成的古生态学数据相结合，以推断北极物种如何受到过去气候，植被和人口连通性变化的影响。它建立在调查人员之前广泛的工作基础上，包括数百个来自永久冻土的14 C年代马骨，这些马骨构成了全球独特的古代DNA档案。