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Träfflista för sökning "WFRF:(Jønsson Knud A.) "

Sökning: WFRF:(Jønsson Knud A.)

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1.
  • Jønsson, Knud A., et al. (författare)
  • Biogeographical history of cuckoo‐shrikes (Aves: Passeriformes) : transoceanic colonization of Africa from Australo-Papua
  • 2010
  • Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 37:9, s. 1767-1781
  • Tidskriftsartikel (refereegranskat)abstract
    • Aim Cuckoo-shrikes and allies (Campephagidae) form a radiation of birds widely distributed in the Indo-Pacific and Africa. Recent studies on the group have been hampered by poor taxon sampling, causing inferences about systematics and biogeography to be rather speculative. With improved taxon sampling and analyses within an explicit spatiotemporal framework, we elucidate biogeographical patterns of dispersal and diversification within this diverse clade of passerine birds. Location Africa, Asia, Australo-Papua, the Pacific, the Philippines and Wallacea. Methods We use model-based phylogenetic methods (MrBayes and garli) to construct a phylogenetic hypothesis of the core Campephagidae (Campephagidae with the exclusion of Pericrocotus). The phylogeny is used to assess the biogeographical history of the group with a newly developed Bayesian approach to dispersal-vicariance analysis (Bayes-diva). We also made use of a partitioned beast analysis, with several calibration points taken from island ages, passerine mitochondrial substitution rates and secondary calibration points for passerine birds, to assess the timing of diversification and dispersal. Results We present a robust molecular phylogeny that includes all genera and 84% of the species within the core Campephagidae. Furthermore, we estimate divergence dates and ancestral area relationships. We demonstrate that Campephagidae originated in Australo-Papua with a single lineage (Pericrocotus) dispersing to Asia early. Later, there was further extensive transoceanic dispersal from Australo-Papua to Africa involving lineages within the core Campephagidae radiation. Main conclusions The phylogenetic relationships, along with the results of the ancestral area analysis and the timing of dispersal events, support a transoceanic dispersal scenario from Australo-Papua to Africa by the core Campephagidae. The sister group to core Campephagidae, Pericrocotus, dispersed to mainland Asia in the late Oligocene. Asia remained uncolonized by the core Campephagidae until the Pliocene. Transoceanic dispersal is by no means an unknown phenomenon, but our results represent a convincing case of colonization over a significant water gap of thousands of kilometres from Australo-Papua to Africa.
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2.
  • Hart Reeve, Andrew, et al. (författare)
  • The formation of the Indo-Pacific montane avifauna
  • 2023
  • Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The processes generating the earth’s montane biodiversity remain a matter of debate. Two contrasting hypotheses have been advanced to explain how montane populations form: via direct colonization from other mountains, or, alternatively, via upslope range shifts from adjacent lowland areas. We seek to reconcile these apparently conflicting hypotheses by asking whether a species’ ancestral geographic origin determines its mode of mountain colonization. Island-dwelling passerine birds at the faunal crossroads between Eurasia and Australo-Papua provide an ideal study system. We recover the phylogenetic relationships of the region’s montane species and reconstruct their ancestral geographic ranges, elevational ranges, and migratory behavior. We also perform genomic population studies of three super-dispersive montane species/clades with broad island distributions. Eurasian-origin species populated archipelagos via direct colonization between mountains. This mode of colonization appears related to ancestral adaptations to cold and seasonal climates, specifically short-distance migration. Australo-Papuan-origin mountain populations, by contrast, evolved from lowland ancestors, and highland distribution mostly precludes their further colonization of island mountains. Our study explains much of the distributional variation within a complex biological system, and provides a synthesis of two seemingly discordant hypotheses for montane community formation.
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3.
  • Irestedt, Martin, et al. (författare)
  • A guide to avian museomics : Insights gained from resequencing hundreds of avian study skins
  • 2022
  • Ingår i: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 22:7, s. 2672-2684
  • Tidskriftsartikel (refereegranskat)abstract
    • Biological specimens in natural history collections constitute a massive repository of genetic information. Many specimens have been collected in areas in which they no longer exist or in areas where present-day collecting is not possible. There are also specimens in collections representing populations or species that have gone extinct. Furthermore, species or populations may have been sampled throughout an extensive time period, which is particularly valuable for studies of genetic change through time. With the advent of high-throughput sequencing, natural history museum resources have become accessible for genomic research. Consequently, these unique resources are increasingly being used across many fields of natural history. In this paper, we summarize our experiences of resequencing hundreds of genomes from historical avian museum specimens. We publish the protocols we have used and discuss the entire workflow from sampling and laboratory procedures, to the bioinformatic processing of historical specimen data.
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4.
  • Jønsson, Knud A, et al. (författare)
  • Ecological and evolutionary determinants for the adaptive radiation of the Madagascan vangas.
  • 2012
  • Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 109:17, s. 6620-5
  • Tidskriftsartikel (refereegranskat)abstract
    • Adaptive radiation is the rapid diversification of a single lineage into many species that inhabit a variety of environments or use a variety of resources and differ in traits required to exploit these. Why some lineages undergo adaptive radiation is not well-understood, but filling unoccupied ecological space appears to be a common feature. We construct a complete, dated, species-level phylogeny of the endemic Vangidae of Madagascar. This passerine bird radiation represents a classic, but poorly known, avian adaptive radiation. Our results reveal an initial rapid increase in evolutionary lineages and diversification in morphospace after colonizing Madagascar in the late Oligocene some 25 Mya. A subsequent key innovation involving unique bill morphology was associated with a second increase in diversification rates about 10 Mya. The volume of morphospace occupied by contemporary Madagascan vangas is in many aspects as large (shape variation)--or even larger (size variation)--as that of other better-known avian adaptive radiations, including the much younger Galapagos Darwin's finches and Hawaiian honeycreepers. Morphological space bears a close relationship to diet, substrate use, and foraging movements, and thus our results demonstrate the great extent of the evolutionary diversification of the Madagascan vangas.
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5.
  • Jønsson, Knud A, et al. (författare)
  • Explosive avian radiations and multi-directional dispersal across Wallacea : evidence from the Campephagidae and other Crown Corvida (Aves).
  • 2008
  • Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 47:1, s. 221-36
  • 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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6.
  • Norman, Janette A, et al. (författare)
  • 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
  • Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 52:2, s. 488-97
  • 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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7.
  • Alström, Per, et al. (författare)
  • Dramatic niche shifts and morphological change in two insular bird species
  • 2015
  • Ingår i: Royal Society Open Science. - : The Royal Society. - 2054-5703. ; 2
  • Tidskriftsartikel (refereegranskat)abstract
    • Colonizations of islands are often associated with rapid morphological divergence. We present two previously unrecognized cases of dramatic morphological change and niche shifts in connection with colonization of tropical forest-covered islands. These evolutionary changes have concealed the fact that the passerine birds madanga, Madanga ruficollis, from Buru, Indonesia, and São Tomé shorttail, Amaurocichla bocagii, from São Tomé, Gulf of Guinea, are forest-adapted members of the family Motacillidae (pipits and wagtails). We show that Madanga has diverged mainly in plumage, which may be the result of selection for improved camouflage in its new arboreal niche, while selection pressures for other morphological changes have probably been weak owing to preadaptations for the novel niche. By contrast, we suggest that Amaurocichla's niche change has led to divergence in both structure and plumage.
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8.
  • Ernst, Mario, et al. (författare)
  • Utilizing museomics to trace the complex history and species boundaries in an avian-study system of conservation concern
  • 2022
  • Ingår i: Heredity. - : Springer Science and Business Media LLC. - 0018-067X .- 1365-2540. ; 128:3, s. 159-168
  • Tidskriftsartikel (refereegranskat)abstract
    • A taxonomic classification that accurately captures evolutionary history is essential for conservation. Genomics provides powerful tools for delimiting species and understanding their evolutionary relationships. This allows for a more accurate and detailed view on conservation status compared with other, traditionally used, methods. However, from a practical and ethical perspective, gathering sufficient samples for endangered taxa may be difficult. Here, we use museum specimens to trace the evolutionary history and species boundaries in an Asian oriole clade. The endangered silver oriole has long been recognized as a distinct species based on its unique coloration, but a recent study suggested that it might be nested within the maroon oriole-species complex. To evaluate species designation, population connectivity, and the corresponding conservation implications, we assembled a de novo genome and used whole-genome resequencing of historical specimens. Our results show that the silver orioles form a monophyletic lineage within the maroon oriole complex and that maroon and silver forms continued to interbreed after initial divergence, but do not show signs of recent gene flow. Using a genome scan, we identified genes that may form the basis for color divergence and act as reproductive barriers. Taken together, our results confirm the species status of the silver oriole and highlight that taxonomic revision of the maroon forms is urgently needed. Our study demonstrates how genomics and Natural History Collections (NHC) can be utilized to shed light on the taxonomy and evolutionary history of natural populations and how such insights can directly benefit conservation practitioners when assessing wild populations.
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10.
  • Irestedt, Martin, et al. (författare)
  • An unexpectedly long history of sexual selection in birds-of-paradise.
  • 2009
  • Ingår i: BMC Evolutionary Biology. - : Springer Science and Business Media LLC. - 1471-2148. ; 9, s. 235-
  • 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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