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

标题：陆桥、无冰走廊和生物群落变化：对冰河时期白令陆桥马的进化和灭绝的影响本研究提出了这样一个问题：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将研究居住在冰河时期白令陆桥（亚洲和北美之间的生物地理连接点）的caballine马如何受到涉及三种不同生物地理屏障/走廊的变化的影响。白令海峡/白令海陆桥控制着欧亚大陆和阿拉斯加之间的传播和基因流动；2. 控制育空地区和美国本土48个州之间基因流动的无冰走廊；和3。在冰河时代的最后3万年里，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代从法国延伸到育空的独特生态系统。本研究将利用新的古基因组学和古环境数据，评估每种假定的基因流动障碍对北极冰期马的丰度、分布和进化轨迹的影响。研究结果将为环境变化和种群碎片化在确定灭绝风险方面所起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。该项目将推动正在迅速发展的古遗传学领域的发展，并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)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)向阿拉斯加农村的土著社区伸出援助之手，d)向AK州费尔班克斯的K-12学生伸出援助之手。每年夏季结束时，职前教师、研究生和pi将为9-12年级制作一个探究活动模块，与当地学校共享。最后，pi将参与专业和公共话语，并在媒体制作中使用结果。

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.