title: Ecological speciation in South Atlantic island finches.
abstract: Examples of sympatric speciation in nature are rare and hotly debated. We describe the parallel speciation of finches on two small islands in the Tristan da Cunha archipelago in the South Atlantic Ocean. Nesospiza buntings are a classic example of a simple adaptive radiation, with two species on each island: an abundant small-billed dietary generalist and a scarce large-billed specialist. Their morphological diversity closely matches the available spectrum of seed sizes, and genetic evidence suggests that they evolved independently on each island. Speciation is complete on the smaller island, where there is a single habitat with strongly bimodal seed size abundance, but is incomplete on the larger island, where a greater diversity of habitats has resulted in three lineages. Our study suggests that the buntings have undergone parallel ecological speciation.
authors.affiliation: Percy Fitz Patrick Institute, Department of Science and Technology/National Research Foundation Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa. Peter.Ryan@uct.ac.za
authors.forename: Peter G
authors.initials: PG
authors.lastname: Ryan
authors.forename: Paulette
authors.initials: P
authors.lastname: Bloomer
authors.forename: Coleen L
authors.initials: CL
authors.lastname: Moloney
authors.forename: Tyron J
authors.initials: TJ
authors.lastname: Grant
authors.forename: Wayne
authors.initials: W
authors.lastname: Delport
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D001266:Atlantic Islands; D001502:Beak / Q000033:anatomy & histology; D005075:Biological Evolution; D049628:Body Size; D004272:DNA, Mitochondrial / Q000032:analysis / Q000235:genetics; D017753:Ecosystem; D046369:Finches / Q000033:anatomy & histology / Q000235:genetics; D049810:Genetic Speciation; D005843:Geography; D018895:Microsatellite Repeats; D012639:Seeds; D012641:Selection, Genetic
chemical_list: D004272:DNA, Mitochondrial