Competitors, Resource Variability, and the Geographic Mosaic of Coevolution for Crossbills and Conifers

生物学的一个根本挑战是了解不同过程在多大程度上产生生物多样性。解释多样化模式的最突出的假设之一是捕食者和猎物之间的军备竞赛。拟议的研究将确定十字鸟(Loxia)和针叶树之间的军备竞赛在多大程度上促进了十字鸟的适应性辐射。这些结果将极大地促进我们对群落背景和资源特征如何影响共同进化的地理镶嵌的理解，从而为进一步的理论进步提供动力。以前使用的技术，包括测量交叉鸟的取食率和圆锥体测量，将被用于测试关于如果交叉鸟和松鼠影响圆锥体结构时应出现的圆锥体特征变化类型的预测，并测试交叉鸟是否以一种相互适应的方式适应变化的圆锥体。这些测试的结果将决定(1)资源特征和竞争对手类型如何影响十字鸟和针叶树的地理镶嵌形式，以及(2)军备竞赛在多大程度上促进了十字鸟的适应性辐射

A fundamental challenge of biology is to understand the extent to which different processes generate biological diversity. One of the most prominent hypotheses to explain patterns of diversification is that of an arms race between predators and their prey. The proposed study will determine the extent to which arms races between crossbills (Loxia) and conifers have contributed to the adaptive radiation of crossbills. These results will greatly advance our understanding of how community context and resource characteristics affect the geographic mosaic of coevolution, and thus provide the impetus for further theoretical advances. Previously used techniques, including measures of crossbill feeding rates and cone measurements, will be used to test predictions concerning the types of changes in cone traits that should arise if crossbills and squirrels have influenced cone structure, and to test whether crossbills have adapted in a reciprocal manner to the changed cones. The results of these tests will determine (1) how resource characteristics and competitor type affect the form of the geographic mosaic for crossbills and conifers and (2) to what extent arms races have contributed to the adaptive radiation of crossbills