Climate driven phenotypic change: macroecology meets quantitative genetics

从土豚到浮游动物，地球上的生命将如何受到气候变化的影响？这个问题的答案对于预测50年或100年后的世界会是什么样子有着巨大的意义。然而，令人担忧的是，科学家们并不知道答案。我们所知道的是，物种在过去已经进化以适应气候变化，在此基础上，似乎有理由预测自然选择的进化可能在当前的气候危机中发挥重要作用。但是，如果气候变化像预期的那样迅速，我们可能会发现，即使是一个物种中最适合的成员也可能不够适合。我将利用奖学金来实现三个主要目标，这将有助于预测物种对气候变化的反应。大多数物种由居住在不同地理区域的许多种群组成，表型不同，表型通常与温度或降雨量相关。我们可以利用这些相关性中的当今模式来判断人口是否需要进化以适应未来变化的气候。例如，在四月期间穿过英格兰南部的一片树林，你可能会看到一片蓝铃花，但在寒冷的苏格兰高地，你需要再等一个月才能看到。气温每年都有波动，因此在某些年份，高地的春季气温可能会上升到与南部通常看到的一样高。在这些年里，我们可以观察到高地风信子开花是否早于南方种群的标准;如果他们不这样做，我们可以推断种群适应了他们平均每年经历的温度。如果温度发生变化，这些适应当地环境的种群将变得不那么适应。我将使用公民科学家收集的物候观测，并由林地信托基金会和英国鸟类信托基金会（BTO）整理，以获得对当地适应是否是负责春季事件的时间为主机的植物和鸟类物种的地理差异的第一个见解。然后，我会问，可塑性或局部适应是否可以根据物种或环境条件的特征来预测。自然选择的作用是当“适合”的个体的表型不同于那些不太适合的个体。为了计算野生种群的表型生存选择，我们需要测量许多个体的性状，我们需要知道哪些个体存活和死亡。大多数测量选择的研究只在一个位置进行。这是不幸的，因为为了预测一个物种将如何进化，我们需要知道选择如何在不同地点和不同时间发生变化。半个多世纪以来，英国各地的鸟类环志者一直在捕捉鸟类，测量每只鸟的翅膀长度，并将这些数据提交给英国鸟类保护组织。我将使用蓝山雀（最常被捕获的鸟类）的这些测量值来估计翅膀长度的选择如何在空间和时间上变化，并测试气候方面是否驱动选择。如果一个种群已经适应了当地的气候，那么如果气候发生变化，自然选择将如何行动？一种可能性是，在整个种群中，生存率会下降，但也有其他可能性，为了区分这些可能性，我将进行一个植物实验。我还将观察鸟类，以测试是否有适应当地条件的筑巢时间的物种特别容易出现人口下降。气候变化的另一个后果是，物种可能会做出不同的反应，破坏物种间的相互作用。我将比较由植物、蝴蝶和鸟类组成的群落，以确定气候变化可能对物种间相互作用造成最大破坏的情况。不同物种和种群适应和应对环境条件的方式令我着迷，对这些过程及其后果的正确理解已经变得紧迫。

From aardvarks to zooplankton, how will life on earth be affected by climate change? The answer to this question has enormous implications for predicting how the world may look in fifty or a hundred years time. Yet, worryingly, scientists do not know the answer. What we do know is that species have evolved to adapt to climate change in the past and, on this basis, it seems reasonable to predict that evolution by natural selection might play an important role in the current climate crisis. But if climate change is as rapid as anticipated, we might find that even the fittest members of a species may not be fit enough. I will use a fellowship to address three main aims that will help in predicting species' responses to climate change. Most species are made up of many populations inhabiting different geographic areas and varying in phenotype, with phenotype often correlating with temperature or rainfall. We can use the present-day patterns in these correlations to see whether populations will need to evolve to a changed climate of the future. For example, walk through a wood in southern England during April and you might see a blanket of bluebells, but in the colder Scottish Highlands you'd need to wait another month to see this. Temperatures fluctuate from year to year, so that in some years the spring temperature in the Highlands may rise as high as that normally seen in the south. In these years, we can observe whether the Highland bluebells flower as early as is the norm for southern populations; if they do not, we can infer that populations are adapted to the temperatures that they experience in an average year. Such locally adapted populations will be rendered less well adapted if temperatures change. I will use observations of phenology collected by citizen scientists and collated by the Woodland Trust and British Trust for Ornithology (BTO) to gain the first insights into whether local adaptation is responsible for geographic differences in the timing of spring events for a host of plant and bird species. I will then ask whether plasticity or local adaptation can be predicted on the basis of the characteristics of species or environmental conditions. Natural selection operates when the phenotypes of 'fit' individuals differ from those of less fit individuals. To calculate phenotypic survival selection for a wild population, we need to measure a trait for lots of individuals and we need to know which individuals survive and perish. Most studies that measure selection do so at just one location. This is unfortunate because, in order to predict how a species will evolve, we need to know how selection varies among locations and over time. For over half a century bird ringers across Britain have caught birds, measuring the wing length of each one and submitting these data to the BTO. I will use these measurements for the blue tit - the most often caught bird - to estimate how selection on wing length varies in space and time and test whether aspects of climate drives selection. If a population has adapted to its local climate, how will selection act if the climate changes? One possibility is that, across the whole population, survival will decrease, but there are other possibilities and, to distinguish these, I will conduct a plant experiment. I will also look at birds to test whether species with nesting times that are adapted to local conditions are especially prone to population decline. Another consequence of climate change is that species may respond differently, disrupting inter-species interactions. I will compare communities composed of plant, butterfly and bird species, to identify cases where climate change may cause most disruption to interactions among species. The ways in which different species and populations adapt and respond to their environmental conditions fascinates me, and gaining a proper understanding of these processes and their consequences has become urgent.