One 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.
