The integration of multiple traits promotes taxonomic stability and should be a major guiding principle for species delimitation. While genomic data have revolutionized the process of delimiting species, such data should be analyzed along with phenotypic, behavioral, and ecological traits that shape individuals across geographic and environmental space. More specifically, studies of species limits must address underlying questions of what limits the distribution of populations, how traits vary in association with different environments, and whether the observed trait differences may lead to speciation through reproductive isolation. Species delimitation requires a broad assessment of population-level variation using multiple lines of evidence, a process known as integrative taxonomy. Moreover, these data suggest that there may be a migratory divide within genetically similar populations of myrtle warblers. Our interpretation is that the evolution of this wintering range and migration route along the Pacific Coast may have facilitated the breeding expansion of myrtle warblers into northwestern North America. Using stable hydrogen isotopes and biometric data, we show that those myrtle warblers wintering along the southern Pacific Coast of North America are likely to breed at high latitudes in Alaska and the Yukon rather than in Alberta or further east. auduboni) captured during their spring migration along the Pacific Coast, south of the narrow region where these two taxa hybridize. We studied both myrtle and Audubon's warblers (S. Myrtle warblers, unlike most other warblers with breeding ranges primarily in eastern North America, have two disjunct overwintering concentrations-one in the southeastern USA and one along the Pacific Coast-and presumably distinct routes to-and-from these locations. Here, we attempt to connect breeding and wintering populations of myrtle warblers (Setophaga coronata coronata) to better understand the possible evolution of distinct migration routes within this species. Many migratory changes are likely to evolve gradually and are therefore difficult to study. New migration routes may evolve in response to selection in favor of reducing distance between breeding and wintering areas, or avoiding navigational barriers. The evolution of novel migration routes can play an important role in range expansions, ecological interactions, and speciation. Long-distance migration is a behavior that is exhibited by many animal groups. It is likely that more cases of avian species of hybrid origin will be revealed by surveys of variation in nuclear DNA and other traits. Broad clines between Audubon’s and black-fronted warblers in AFLP markers call into question the validity of these two forms as full species nevertheless, our results suggest that the Audubon’s warbler probably originated through hybridization between two long-diverged species. Audubon’s warblers also carry two deeply divergent mitochondrial DNA lineages, each shared with only one putative parental form. Analysis of nuclear amplified fragment length polymorphism (AFLP) and sequence markers shows that Audubon’s warblers are genetically intermediate and carry a mixture of alleles otherwise found only in one or the other of their putative parental species. We investigate whether the Audubon’s warbler (Dendroica auduboni), one of four visually distinct species in the yellow-rumped warbler complex, has originated through hybridization between two other species in this group, the myrtle warbler (D. Several animal species have recently been shown to have hybrid origins, but no avian examples have been documented with molecular evidence.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |