Diversifying Coevolution and Ecological Speciation in Crossbills

[02:12 . 27]本杰明进化生物学的核心问题之一是了解导致新物种产生的过程。这个项目将确定红嘴鸦和黑松之间的共同进化军备竞赛是否以及如何导致红嘴鸦（类雀类鸟类）的新物种。首先，将使用标记-再捕获方法来确定共同进化的自然选择是否导致了杂交鸟种群之间观察到的形态差异。其次，鸟舍实验和实地研究将解决生殖隔离（即物种形成）如何作为分化选择的副产品发生的问题。最后，利用AFLP引物进行遗传研究，以确定不同红嘴鸦种群之间的遗传分化程度，并建立所有北美红嘴鸦的系统发育。这项工作旨在将两个最重要的进化过程，共同进化军备竞赛和物种形成，与生物多样性的模式和多样性的地理模式如何产生联系起来。能够记录这种共同进化的相互作用，以及它们现在对新物种起源的真正可能性，不仅令人兴奋，而且可能提供有助于防止不受欢迎的灭绝的见解。这种相互作用很少在任何分类群中得到很好的记录，更不用说鸟类了，它们吸引了许多市民的注意。

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.