title: Molecular and phenotypic divergence in the bluethroat (Luscinia svecica) subspecies complex.
abstract: Subspecies complexes may provide valuable insights into the early stages of the speciation process. The bluethroat (Luscinia svecica) consists of many morphologically distinct subspecies that differ most strikingly in the ornamental colour pattern of the male throat. We investigated the genetic and phenotypic differentiation in this subspecies complex, using (i) microsatellite genotyping (11 loci) of a sample of 364 individuals from bluethroat populations in Europe and Asia, and (ii) spectrometric and morphological measurements of a sample of 131 museum skin specimens. Population genetic analyses, based on microsatellite allele frequency variation, revealed a slight but significant overall population differentiation (F(ST) = 0.042). There was a well-differentiated southern group of subspecies with white or no throat spots and a less-differentiated northern group of chestnut-spotted populations. Phylogenetic analyses indicated that the southern all-blue and white-spotted forms are ancestral to the chestnut-spotted subspecies. In addition to the qualitative variation in throat plumage pattern already described in the literature, we found significant quantitative variation among subspecies in hue, chroma and brightness of the ultraviolet (UV)/blue throat coloration, and this variation seemed to be unrelated to the phylogenetic distance between subspecies.
authors.affiliation: National Centre for Biosystematics, Natural History Museum, University of Oslo, PO Box 1172 Blindern, 0318 Oslo, Norway.
authors.forename: Arild
authors.initials: A
authors.lastname: Johnsen
authors.forename: Staffan
authors.initials: S
authors.lastname: Andersson
authors.forename: Javier Garcia
authors.initials: JG
authors.lastname: Fernandez
authors.forename: Bart
authors.initials: B
authors.lastname: Kempenaers
authors.forename: Václav
authors.initials: V
authors.lastname: Pavel
authors.forename: Sophie
authors.initials: S
authors.lastname: Questiau
authors.forename: Michael
authors.initials: M
authors.lastname: Raess
authors.forename: Eirik
authors.initials: E
authors.lastname: Rindal
authors.forename: Jan T
authors.initials: JT
authors.lastname: Lifjeld
mesh_terms: D000818:Animals; D003116:Color; D005241:Feathers / Q000502:physiology; D005260:Female; D049810:Genetic Speciation; D014644:Genetic Variation; D005828:Genetics, Population; D008297:Male; D018895:Microsatellite Repeats; D010641:Phenotype; D010802:Phylogeny; D020308:Songbirds / Q000235:genetics / Q000502:physiology*