Habitat selection and ecological speciation in Galápagos warbler finches ( Certhidea olivacea and Certhidea fusca )
- 22 April 2005
- journal article
- research article
- Published by The Royal Society in Proceedings Of The Royal Society B-Biological Sciences
- Vol. 272 (1565) , 819-826
- https://doi.org/10.1098/rspb.2004.3030
Abstract
We investigated phylogeographic divergence among populations of Galápagos warbler finches. Their broad distribution, lack of phenotypic differentiation and low levels of genetic divergence make warbler finches an appropriate model to study speciation in allopatry. A positive relationship between genetic and geographical distances is expected for island taxa. Warbler finches actually showed a negative isolation by distance relationship, causing us to reject the hypothesis of distance‐limited dispersal. An alternative hypothesis, that dispersal is limited by habitat similarity, was supported. We found a positive correlation between genetic distances and differences in maximum elevation among islands, which is an indicator of ecological similarity. MtDNA sequence variation revealed monophyletic support for two distinct species. Certhidea olivacea have recently dispersed among larger central islands, while some Certhidea fusca have recently dispersed to small islands at opposite ends of the archipelago. We conclude that females have chosen to breed on islands with habitats similar to their natal environment. Habitat selection is implicated as an important component of speciation of warbler finches, which is the earliest known divergence of the adaptive radiation of Darwin's finches. These results suggest that small populations can harbour cryptic but biologically meaningful variation that may affect longer term evolutionary processes.Keywords
This publication has 50 references indexed in Scilit:
- Extinction behind our backs: the possible fate of one of the Darwin’s finch species on Isla Floreana, GalápagosBiological Conservation, 2005
- Reversed sexual dimorphism in the beak of a finchIbis, 2003
- PHYLOGEOGRAPHY AND HISTORY OF GIANT GALAPAGOS TORTOISESEvolution, 2002
- IS THE PARTIAL MANTEL TEST INADEQUATE?Evolution, 2002
- PHYLOGENETIC RELATIONSHIPS AND MORPHOLOGICAL DIVERSITY IN DARWIN'S FINCHES AND THEIR RELATIVESEvolution, 2002
- Cryptic genetic variation and paraphyly in ravensProceedings Of The Royal Society B-Biological Sciences, 2000
- Cultural Inheritance of Song and Its Role in the Evolution of Darwin's FinchesEvolution, 1996
- Population structure and gene flow in Stomion: a species swarm of flightless beetles of the Galápagos IslandsHeredity, 1995
- Historical Biogeography of the Bananaquit (Coereba flaveola) in the Caribbean Region: A Mitchondrial DNA AssessmentEvolution, 1994
- Molecular Genetic Relationships of the Extinct Dusky Seaside SparrowScience, 1989