Diversifying Coevolution and Ecological Speciation in Crossbills

进化生物学的核心问题之一是理解导致新物种产生的过程。这个项目将确定红十字鸟和松树之间的共同进化军备竞赛是否以及如何导致红十字鸟(类似雀类鸟类)的新物种。首先，标记和重新捕获方法将被用来确定作为共同进化的结果的自然选择是否导致了观察到的十字鸟种群之间的形态差异。其次，鸟类实验和实地研究将探讨生殖隔离(即物种形成)可能是如何作为分歧选择的副产品而发生的。最后，使用AFLP引物的遗传研究将被用来确定不同交叉鸟种群之间的遗传分化程度，并建立所有北美交叉鸟的系统发育。这项工作旨在将两个最重要的进化过程--共同进化的军备竞赛和物种形成--与生物多样性的格局以及多样性的地理格局如何产生联系起来。能够记录这种共同进化的相互作用--它们现在真正有可能促进新物种的起源--不仅令人兴奋，还可能提供有助于防止不受欢迎的灭绝的见解。在任何分类群中，这种相互作用很少被很好地记录下来，更不用说吸引了许多公民注意的鸟类了。

0212271BenkmanOne of the central problems in evolutionary biology is to understand the processes that lead to new species. This project will determine whether and how the coevolutionary arms race between red crossbills and lodgepole pine is leading to new species of red crossbills (finch-like birds). First, mark-and-recapture methods will be used to determine whether natural selection as a result of coevolution has caused the observed morphological divergence between crossbill populations. Second, aviary experiments and field studies will address how reproductive isolation (i.e., speciation) might have occurred as a by-product of divergent selection. Finally, genetic studies using AFLP primers will be used to determine the extent of genetic differentiation between different crossbill populations and to develop a phylogeny of all North American red crossbills. This work aims to link two of the most important evolutionary processes, coevolutionary arms races and speciation, to patterns of biodiversity and to how geographic patterns of diversity arise. Being able to document such coevolutionary interactions, with the real possibility that they are now contributing to the origin of new species, is not only exciting, but may also provide insights that will help prevent undesirable extinctions. Such interactions have rarely been well documented for any taxa, let alone for birds, which capture the attention of many citizens.