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

生物学的一个基本挑战是了解不同过程产生生物多样性的程度。解释多样化模式的一个最突出的假设是捕食者和猎物之间的军备竞赛。拟议的研究将确定在多大程度上交叉杉（Loxia）和针叶树之间的军备竞赛促成了交叉杉的适应性辐射。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协同进化的地理马赛克的理解，从而为进一步的理论发展提供动力。以前使用的技术，包括交叉喙进食率和锥体测量的测量，将用于测试关于锥体特征变化类型的预测，如果交叉喙和松鼠影响了锥体结构，并测试交叉喙是否以相互的方式适应了变化的锥体。这些测试的结果将确定(1)资源特征和竞争对手类型如何影响交叉树种和针叶树的地理镶嵌形式；(2)军备竞赛在多大程度上促进了交叉树种的适应性辐射

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