The Imprint of History on Communities of North American and Asian Warblers

• Published in: The American naturalist 2000-10, Vol.156 (4), p.354-367
• Main Authors: Price, Trevor, Lovette, Irby J., Bermingham, Eldredge, Gibbs, H. Lisle, Richman, Adam D.
• Format: Article
• Language: English
• Subjects: Beak; Biological taxonomies; Birds; Body size; Dendroica; Ecology; Evolution; Ornithology; Phylloscopus; Phylogeny; Population ecology; Speciation; Species; Synecology; Warblers
• ISSN: 0003-0147; 1537-5323
• DOI: 10.1086/303397

The ecology of the component species of an adaptive radiation is likely to be influenced by the form of the founding ancestor to the radiation, its timing, and rates of speciation and extinction. These historical features complement environmental selection pressures. They imply that, if the history of the species’ radiations are very different, ecological communities are unlikely to be completely convergent even when placed in identical environments. We compare the adaptive radiation of theDendroicawarblers of North America with that of thePhylloscopuswarblers of Asia. We consider the ecology of the species in two localities where species’ diversity is very high (New Hampshire, U.S.A., and Kashmir, India, respectively) and contrast the history of the two radiations on the basis of a molecular (mitochondrial cytochrome b) phylogeny. By comparison with thePhylloscopus, theDendroicaare on average larger and morphologically more similar to one another. Although there is some similarity between theDendroicaandPhylloscopuscommunities, they differ in foraging behavior and in associations of morphology with ecological variables. TheDendroicalikely reflect an early Pliocene radiation and are two to four times younger than thePhylloscopus. They probably had a colorful sexually dichromatic ancestor, implicating sexual selection in the production of the many ecologically similar species. ThePhylloscopusare much older and probably had a drab, monomorphic ancestor. Given the difference in ages of the two radiations, it is plausible that the close species’ packing of theDendroicawarblers is a transient phenomenon. If this is the case, community structure evolves on the timescales of millions of years. Differences in ancestry and timing of the species’ radiations can be related to the different biogeography of the two regions. This implies that the historical imprint on adaptive radiations could be predicted on the basis of the attributes of ancestors and biogeographical context.