The Genome of the "Great Speciator" Provides Insights into Bird Diversification.
Among birds, white-eyes (genus Zosterops) have diversified so extensively that Jared Diamond and Ernst Mayr referred to them as the "great speciator." The Zosterops lineage exhibits some of the fastest rates of species diversification among vertebrates, and its members are the most prolific passerine island colonizers. We present a high-quality genome assembly for the silvereye (Zosterops lateralis), a white-eye species consisting of several subspecies distributed across multiple islands. We investigate the genetic basis of rapid diversification in white-eyes by conducting genomic analyses at varying taxonomic levels. First, we compare the silvereye genome with those of birds from different families and searched for genomic features that may be unique to Zosterops. Second, we compare the genomes of different species of white-eyes from Lifou island (South Pacific), using whole genome resequencing and restriction site associated DNA. Third, we contrast the genomes of two subspecies of silvereye that differ in plumage color. In accordance with theory, we show that white-eyes have high rates of substitutions, gene duplication, and positive selection relative to other birds. Below genus level, we find that genomic differentiation accumulates rapidly and reveals contrasting demographic histories between sympatric species on Lifou, indicative of past interspecific interactions. Finally, we highlight genes possibly involved in color polymorphism between the subspecies of silvereye. By providing the first whole-genome sequence resources for white-eyes and by conducting analyses at different taxonomic levels, we provide genomic evidence underpinning this extraordinary bird radiation.
Department of Life Sciences, Imperial College London, Ascot, United Kingdom.
Luca
L
Cornetti
Department of Life Sciences, Imperial College London, Ascot, United Kingdom Unit of Evolutionary Biology/Systematic Zoology, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany.
Luis M
LM
Valente
Department of Life Sciences, Imperial College London, Ascot, United Kingdom.
Luke T
LT
Dunning
Department of Life Sciences, Imperial College London, Ascot, United Kingdom.
Xueping
X
Quan
Department of Life Sciences, Imperial College London, Ascot, United Kingdom Royal Society for the Protection of Birds, Pavilion View, Brighton, Bedfordshire, United Kingdom NERC Biomolecular Analysis Facility (NBAF) Department of Animal & Plant Sciences, University of Sheffield, Sheffield, United Kingdom.
Richard A
RA
Black
Waco me Wela Association, Tribu de Luecila, Lifou, New Caledonia.
Olivier
O
Hébert
Department of Life Sciences, Imperial College London, Ascot, United Kingdom v.savolainen@imperial.ac.uk.
Vincent
V
Savolainen
D000818:Animals; D001717:Birds / Q000145:classification / Q000235:genetics; D019143:Evolution, Molecular; D049810:Genetic Speciation; D016678:Genome; D046109:Passeriformes / Q000235:genetics*; D010802:Phylogeny
demography; gene duplication; genome evolution; morphological divergence; phylogenomics; positive selection