| 1. |
- Irestedt, Martin, et al.
(författare)
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An unexpectedly long history of sexual selection in birds-of-paradise.
- 2009
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Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 9, s. 235-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The birds-of-paradise (Paradisaeidae) form one of the most prominent avian examples of sexual selection and show a complex biogeographical distribution. The family has accordingly been used as a case-study in several significant evolutionary and biogeographical syntheses. As a robust phylogeny of the birds-of-paradise has been lacking, these hypotheses have been tentative and difficult to assess. Here we present a well supported species phylogeny with divergence time estimates of the birds-of-paradise. We use this to assess if the rates of the evolution of sexually selected traits and speciation have been excessively high within the birds-of-paradise, as well as to re-interpret biogeographical patterns in the group.RESULTS: The phylogenetic results confirm some traditionally recognized relationships but also suggest novel ones. Furthermore, we find that species pairs are geographically more closely linked than previously assumed. The divergence time estimates suggest that speciation within the birds-of-paradise mainly took place during the Miocene and the Pliocene, and that several polygynous and morphologically homogeneous genera are several million years old. Diversification rates further suggest that the speciation rate within birds-of-paradise is comparable to that of the enitre core Corvoidea.CONCLUSION: The estimated ages of morphologically homogeneous and polygynous genera within the birds-of-paradise suggest that there is no need to postulate a particularly rapid evolution of sexually selected morphological traits. The calculated divergence rates further suggest that the speciation rate in birds-of-paradise has not been excessively high. Thus the idea that sexual selection could generate high speciation rates and rapid changes in sexual ornamentations is not supported by our birds-of-paradise data. Potentially, hybridization and long generation times in polygynous male birds-of-paradise have constrained morphological diversification and speciation, but external ecological factors on New Guinea may also have allowed the birds-of-paradise to develop and maintain magnificent male plumages. We further propose that the restricted but geographically complex distributions of birds-of-paradise species may be a consequence of the promiscuous breeding system.
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| 2. |
- Jønsson, Knud A, et al.
(författare)
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Explosive avian radiations and multi-directional dispersal across Wallacea : evidence from the Campephagidae and other Crown Corvida (Aves).
- 2008
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 47:1, s. 221-36
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Tidskriftsartikel (refereegranskat)abstract
- The systematic relationships among avian families within Crown Corvida have been poorly studied so far and as such been of limited use for biogeographic interpretations. The group has its origin in Australia and is thought to have colonized Africa and the New World via Asia beginning some 35 Mya when terranes of Australian origin approached Asian landmasses. Recent detailed tectonic mapping of the origin of land masses in the region around Wallace's line have revealed a particularly complex movement of terranes over the last 20-30 Myr. Thus the biogeographic dispersal pattern of Crown Corvida is a particularly exciting case for linking vicariance and dispersal events with Earth history. Here we examine phylogenetic affinities among 72 taxa covering a broad range of genera in the basal radiations within Crown Corvida with an emphasis on Campephagidae and Pachycephalidae. Bayesian analyses of nuclear DNA sequence data identified the family Campephagidae as monophyletic but the large genus Coracina is not. Within the family Pachycephalidae the genera Pachycephala and Colluricincla are paraphyletic with respect to each other. The resulting phylogeny suggests that patterns of dispersal across Wallace's line are complex and began at least 25 Mya. We find evidence of explosive radiations and multi-directional dispersal within the last 10 Myr, and three independent long distance ocean dispersal events between Wallacea and Africa at 10-15 Mya. Furthermore, the study reveals that in the Campephagidae a complex series of dispersal events rather than vicariance is the most likely explanation for the current biogeographic pattern in the region.
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| 3. |
- Norman, Janette A, et al.
(författare)
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A multi-gene phylogeny reveals novel relationships for aberrant genera of Australo-Papuan core Corvoidea and polyphyly of the Pachycephalidae and Psophodidae (Aves : Passeriformes).
- 2009
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 52:2, s. 488-97
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Tidskriftsartikel (refereegranskat)abstract
- The core Corvoidea is the largest and most diverse oscine assemblage within the Australo-Papuan region. Although central to an understanding of the evolutionary history and biogeography of the group the composition and intergeneric relationships of the Australo-Papuan radiation remain poorly understood. Here we analysed DNA sequence data from two nuclear gene regions and the mitochondrial cytochrome b gene, for 40 species of core Corvoidea to test the systematic affinities of key Australo-Papuan lineages. The families Pachycephalidae (whistlers, shrike-thrushes and allies) and Psophodidae (whipbirds, quail-thrush and allies) were both recovered as polyphyletic assemblages. The core pachycephaline assemblage comprised Pachycephala, Colluricincla, parts of Pitohui, and Falcunculus with the remaining genera resolving as four divergent lineages with no clearly defined affinities. Ptilorrhoa and Cinclosoma (Cinclosomatidae) formed a clade separate from Psophodes (Psophodidae) but neither clade showed clear affinities to any other taxa. Novel relationships were also identified for three aberrant New Guinean genera; ditypic Machaerirhynchus and monotypic Rhagologus were both nested within an assemblage that included the Artamidae and African malaconotoids (bush-shrikes and allies) while the enigmatic Ifrita was found to be part of an assemblage that included the Monarchidae and Paradisaeidae.
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