Genetic structure and adaptation at a dynamic range margin

我们目前正处于全球变暖的时期，这对全世界的物种分布产生了巨大的影响。许多物种的北方分布区边界在地理上正在扩大，而其南部周边分布区的范围边缘则受到不太适宜的生境以及人类活动和生物压力增加造成的隔离程度增加的影响。这些分布变化将对生物多样性和生态过程产生深远影响，需要详细了解种群范围变化的原因和后果。该项目将研究飞鼠（Glaucomys sp.）在安大略进行了一次重要的“自然实验”。 南方飞鼠的活动范围在10年内扩大了约200公里，然而，在2003-04年，寒冷的冬天和食物不足的综合影响导致种群在一年内收缩了相等的距离。 该项目将调查任何幸存的南方飞鼠种群或杂交的北方x南方飞鼠，它们可能已经适应了当地的急性气候事件。候选适应基因可能参与温度调节，促进当地适应寒冷的冬天在范围前或在任何幸存的口袋的特点。 我们还将研究气候变暖趋势和栖息地破碎化对飞鼠的协同效应，因为它们通过发达的安大略景观扩展。 在未来几十年里，重要的是增加我们对气候变暖和日益随机的恶劣天气条件（如2003-04年安大略冬季）对野生动物种群的范围扩张和当地适应的综合影响的理解。

We are currently in a period of global warming that is having dramatic effects on species distributions worldwide. Geographic expansions of northern range boundaries are occurring for many species, while the range margins at their southern peripheral distribution are impacted by less suitable habitat and increased isolation resulting from anthropogenic activities and increased biotic stress. These distributional changes will have profound effects on biodiversity and ecological processes and require a detailed understanding of the causes and consequences of range shifts at the population level. This project will study flying squirrels (Glaucomys sp.) that have undergone an important "natural experiment" in Ontario. Southern flying squirrels expanded their range by approximately 200 km over a 10-year period, however, in 2003-04, the combined effects of a cold winter and low food caused the population to contract by an equivalent distance in one year. This project will survey any surviving southern flying squirrel populations or hybrid northern x southern flyers that may have been adapted to the acute local climatic event. Candidate adaptive genes potentially involved in thermoregulation that promoted local adaptation to the colder winter at the range front or in any surviving pockets will be characterized. We will also examine the synergistic effects of warming trends and habitat fragmentation on flying squirrels as they expand through the developed Ontario landscape. It will be important over the next few decades to increase our understanding the combined effects of climatic warming and increasingly random harsh weather conditions, such as the 2003-04 Ontario winter, on range expansions and local adaptation in wildlife populations.