DISSERTATION RESEARCH: Thrice through Beringia? Unraveling the evolution of North American pikas

俄罗斯和阿拉斯加之间的无冰走廊被称为Beringia，它促进了跨洲物种的交流，并在上一个冰河时代为许多物种提供了避难所。因此，它是检验有关许多物种的扩散和生存理论的重要舞台。这一地区的气候变化很快，预计最近北极地区的变暖趋势最强烈。小型哺乳动物，如衣领鼠兔，提供了有关气候变化影响的重要信息。只有在阿拉斯加和加拿大西北部的距骨山坡上才能发现有领鼠兔。这是仅有的两种北美鼠兔之一，它们的活动范围远远超过其他物种。当鼠兔的化石记录与遗传数据对比时，提出了衣领鼠兔近期活动范围收缩和随后快速扩张的历史。该奖项支持阿拉斯加大学费尔班克斯分校的一名博士生的研究，这与颈鼠兔从南部避难所进入北部栖息地的观点一致。这项研究对理解北极和亚北极生态系统中谱系的持久性和进化具有重要意义。这将有助于确定北部地区的动物群更替速度，并区分偶发事件和反复出现的进化趋势。该项目还为了解气候变化对一种标志性高山哺乳动物种群结构的长期影响提供了重要的经验背景。

The ice-free corridor between Russia and Alaska, known as Beringia, has facilitated transcontinental species exchange and provided a refugium for many species during the last ice age. It is therefore an important arena for testing theories regarding dispersal and survival of many species. Climate has shifted rapidly in this region, and recent warming trends are predicted to be strongest in the Arctic. Small mammals, such as the collared pika, provide important information on the effects of climate change. Collared pikas are found only on talus slopes in Alaska and northwest Canada. This is one of only two species of North American pikas, and their range is far to the north of the other species. When the fossil record of pikas is contrasted with genetic data, a history of recent range contraction and subsequent rapid expansion is suggested for collared pikas. This is consistent with the idea that collared pikas entered their northern habitat from refugia in the south, and not from Russia.This award supports the research of a doctoral degree candidate at the University of Alaska, Fairbanks. The study has implications for understanding the persistence and evolution of lineages in arctic and subarctic ecosystems. It will help determine the rate of faunal turnover in northern regions, and distinguish between chance events and recurrent evolutionary trends. This project also provides an important empirical context for understanding the long-term effects of climate change on the demographics of an iconic alpine mammal.