International Research Fellowship Program (IRFP): Birds Eating Bugs: The Geographic Mosaic of Preator-Mediated Natural Selection

0601971 Kuchta国际研究奖学金计划使美国科学家和工程师能够在国外进行9至24个月的研究。 该计划的奖项提供了联合研究的机会，以及使用独特或互补的设施，专业知识和国外的实验条件。Kuchta与瑞典隆德的隆德大学的Erik Svensson博士合作。在自然系统中，个体如果要将基因传递给后代，就必须避免被吃掉。因此，捕食对生物体的适应性有很大的影响。然而，捕食的选择性结果很难研究，因为捕食会将个体从种群中剔除，从而阻止对它们的测量。研究捕食强度的地理结构就更困难了。与瑞典南部隆德大学的Erik Svensson合作，这项研究解决了一种有效的鸟类捕食者--翘尾雀--对豆娘（Calopteryx）施加的选择梯度的地理镶嵌。 Wagtail捕捉豆娘并返回“屠宰站”，在那里它们会移除翅膀并吃掉身体。 从屠宰站收集翅膀，并将它们与自然种群中存在的变异进行比较，使我们能够计算自然选择对各种翅膀特征的强度和方向，例如颜色斑块的形状和大小。先前的研究已经证明了一个种群中翅膀性状的自然选择，但目前的研究将其扩展到22个种群，包括捕食强度的“热点”和“冷点”。 此外，高分辨率分子标记正被用于测量种群之间的遗传交换量。 这些数据使我们能够量化种群内的局部适应与种群间的基因流之间的相互作用，具有不同的自适应最优值。 除了影响捕食概率外，豆娘翅膀上的色块还在雌性选择（性选择）和物种识别（不同物种采用的视觉线索相互区分）中发挥作用。 各种选择力之间的权衡正在审查操纵翅斑的大小在豆娘的自然种群，同时测量自然选择，性选择和种间相互作用的大小。该实验在四个种群中重复，包括两个捕食强度的“热点”和两个“冷点”。 捕食者-食饵动力学对自然系统的动力学有着极其重要的意义。这项研究采取了一种综合的，空间上明确的方法来推进我们对自然种群中正在进行的选择过程的理解。

0601971KuchtaThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Shawn R. Kuchta to work with Dr. Erik Svensson at Lund University in Lund, Sweden.In natural systems, individuals must avoid being eaten if they are to pass their genes on to future generations. For this reason, predation has a strong impact on organismal fitness. The selective consequences of predation are difficult to study, however, because predation removes individuals from the population and thereby prevents their measurement. Studying the geographic structure of predation intensities is even more difficult. In collaboration with Erik Svensson at Lund University in southern Sweden, this research addresses the geographic mosaic of selection gradients imposed on damselflies (Calopteryx) by an efficient avian predator, the wagtail. Wagtails catch damselflies and return to "slaughter stations" where they remove the wings and consume the body. Collecting wings from slaughter stations and comparing them to the variation present in natural populations allows us to calculate the strength and direction of natural selection on various wing traits, such as the shape and size of color patches. Prior research has demonstrated natural selection on wing traits in one population, but the current research extends this to 22 populations, including "hotspots" and "coldspots" of predation intensity. In addition, high resolution molecular markers are being used to measure the amount of genetic exchange among populations. This data allows us to quantify the interaction between local adaptation within populations versus gene flow among populations with differing adaptive optima. In addition to influencing predation probabilities, color patches on the wings of damselflies function in female choice (sexual selection) and species recognition (visual clues different species employ tell each other apart). The trade-off among the various selective forces is being examined by manipulating the wing patch size in natural populations of damselflies and simultaneously measuring the magnitude of natural selection, sexual selection, and interspecific interactions. This experiment is being replicated in four populations, including two "hotspots" and two "coldspots" of predation intensity. Predator-prey dynamics are of profound importance to the dynamics of natural systems. This research takes an integrative, spatially explicit approach to advancing our understanding of the ongoing selective processes operating in natural populations.