title: Understanding the colonization history of the Galápagos flycatcher (Myiarchus magnirostris).
abstract: The Galápagos archipelago has never been connected to any continental land masses, so it is of interest to know the colonization and diversification history of its endemic species. We analyzed the phylogenetic placement of the endemic Galápagos flycatcher, M. magnirostris, within Myiarchus by using the genes ND2 and cytb (1970 bp) to compare 16 of the 22 species that comprise this genus. We also analyzed variability in cytb sequences from 154 M. magnirostris individuals captured on seven Galápagos islands. Our phylogenetic analyses recovered the two main Myiarchus clades that had been described by previous genetic, morphological, and vocal analyses. M. magnirostris is monophyletic and its closest living relative is M. tyrannulus from Mexico and Central America. The average age for the split node between these two groups was approximately 850,000 years (95% C.I. 630,735-1,087,557). M. tyrannulus, M. nugator, M. nuttingi, M. sagrae, and M. stolidus are not monophyletic species. Within M. magnirostris itself, we found low nucleotide and haplotype diversities (π=0.0009 and h=0.4913, respectively) and a high genetic structure among populations. We also detected a star-shaped haplotype network and significantly negative values for Tajima's D and Fu's Fs for this species. Our results suggest that M. magnirostris originated from a single colonization event and had a recent population expansion in the Galápagos archipelago.
authors.affiliation: Department of Biology and Whitney R. Harris World Ecology Center, University of Missouri-St. Louis, One University Boulevard, 223 Research Building, Saint Louis, MO 63121, USA. eloisa.sari@gmail.com
authors.forename: Eloisa H R
authors.initials: EH
authors.lastname: Sari
authors.forename: Patricia G
authors.initials: PG
authors.lastname: Parker
mesh_terms: D000818:Animals; D001483:Base Sequence; D045303:Cytochromes b / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D004484:Ecuador; D019143:Evolution, Molecular; D049810:Genetic Speciation; D014644:Genetic Variation; D016678:Genome; D008969:Molecular Sequence Data; D009245:NADH Dehydrogenase / Q000235:genetics*; D010802:Phylogeny; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020308:Songbirds / Q000145:classification* / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial; D045303:Cytochromes b; D009245:NADH Dehydrogenase