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.

标题：陆桥、无冰走廊和生物群落转变：对冰河时代白令陆桥马的进化和灭绝的影响这项研究提出：大型北极哺乳动物种群之间的连通性对于维持遗传多样性、影响进化变化、并减轻灭绝风险？哪些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 将研究居住在冰河时代白令海峡（亚洲和北美之间的生物地理连接器）的卡巴林马如何受到涉及三个不同生物地理屏​​障/走廊的变化的影响（1.白令海峡/白令陆桥，控制了扩散）以及欧亚大陆和阿拉斯加之间的基因流动；2. 无冰走廊，控制着育空地区和下游 48 个州之间的基因流动；3. 生物群落；在冰河时代的最后 3 万年里，猛犸草原（冰河时期从法国延伸到育空地区的独特生态系统）的空间连续性发生了周期性的变化。这项研究将利用新的古基因组和古环境数据来评估这些假定的基因流动障碍对北极冰河时代马的丰度、分布和进化轨迹的影响。研究结果将为了解环境变化和人口破碎在确定灭绝风险中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取得进展，并进一步推动古基因组生态学这一全新学科的发展。更广泛的影响计划侧重于：a) 为研究生提供研究和专业发展机会，b) 为渴望成为 STEM 高中教师的本科生提供新的培训机会，c) 向阿拉斯加农村的原住民社区推广，以及 d) 向阿拉斯加州费尔班克斯的 K-12 学生。每年暑假结束时，职前教师、研究生和 PI 都会制作 9-1​​2 年级的探究活动模块，并与当地学校共享。最后，PI将参与专业和公共讨论，并将研究结果用于媒体制作。这是一项跨学科研究，将尖端古基因组技术与新合成的古生态数据相结合，以推断北极物种如何受到过去气候变化的影响，植被和人口连通性。它建立在研究人员之前所做的大量工作的基础上，其中包括数百块来自永久冻土层的 14C 年代的马骨，这些马骨构成了全球独特的古代 DNA 档案。