Linking behavioural and landscape ecology of hybridization in mammals

当代气候变化的快速步伐意味着，由于激烈的自然选择，我们可能正在进入一个快速适应的时代。种间杂交通常被认为是气候变化的结果，但它也可能是快速适应的重要来源。这是因为杂交是一种相对快速的方法，可以获得新的基因组合，从而在生物体中产生新的特征。在适当的环境条件下，如果这些新性状具有适应性优势，它们可能会在种群中持续存在。我的研究项目包括测试对导致种间杂交的动物行为的预测，然后评估这些行为对种群遗传结构的大规模影响。我和我的同事在安大略省的一个接触区观察到南北鼯鼠的杂交，这个接触区最近出现在这两个物种之间，因为南方物种的活动范围扩大了。我们认为，飞鼠物种之间的杂交是由冬天蜷缩在一起（或社会温度调节）的行为需要促进的，因为交配发生在冬末，而松鼠仍然处于热应激状态。如果这两种松鼠挤在一起，可能会导致我们在接触区观察到的杂交。我们将开展观察研究和实验，以验证北松鼠和南松鼠会共同进行社会体温调节的假设。然后，我们将进行大尺度遗传结构分析，以评估杂交鼯鼠的分布、遗传和形态结构。

The rapid pace of contemporary climate change means that we may be entering an era of rapid adaptation due to intense natural selection. Interspecific hybridization is often considered to be a consequence of climate change, but it is also potentially an important source of rapid adaptation. This is because hybridization is a relatively fast way to arrive at new combinations of genes, which may then produce novel traits in organisms. Under appropriate environmental conditions, these novel traits may then persist in the population if they confer a fitness advantage. My research program involves testing predictions about animal behaviours that lead to interspecific hybridization, and then assessing large-scale consequences of these behaviours on the genetic structure of populations. My colleagues and I have observed hybridization between northern and southern flying squirrels in a contact zone that has recently emerged between these species in Ontario due to range expansion by the southern species. We think that hybridization between flying squirrel species is promoted by the behavioural need to huddle (or socially thermoregulate) in winter, since mating occurs in late winter while squirrels are still thermally stressed. If squirrels of both species huddle together, that could lead to the hybridization we have observed in the contact zone. We will carry out observational studies and experiments to test the hypothesis that northern and southern flying squirrels will socially thermoregulate together. We will then carry out analyses of large-scale genetic structure to assess the distribution, genetic, and morphological structure of hybrid flying squirrels.