| 1. |
- Johansson, Ulf S, et al.
(författare)
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Build-up of the Himalayan avifauna through immigration : A biogeographical analysis of the Phylloscopus and Seicercus warblers
- 2007
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Ingår i: Evolution. - : Wiley. - 0014-3820 .- 1558-5646. ; 61:2, s. 324-333
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Tidskriftsartikel (refereegranskat)abstract
- The Himalayan mountain range is one of the most species-rich areas in the world, harboring about 8% of the world's bird species. In this study, we compare the relative importance of immigration versus in situ speciation to the build-up of the Himalayan avifauna, by evaluating the biogeographic history of the Phylloscopus/Seicercus warblers, a speciose clade that is well represented in Himalayan forests. We use a comprehensive, multigene phylogeny in conjunction with dispersal-vicariance analysis to discern patterns of speciation and dispersal within this clade. The results indicate that virtually no speciation has occurred within the Himalayas. Instead, several speciation events are attributed to dispersal into the Himalayas followed by vicariance between the Himalayas and China/Southeast Asia. Most, perhaps all, of these events appear to be pre-Pleistocene. The apparent lack of speciation within the Himalayas stands in contrast to the mountain-driven Pleistocene speciation suggested for the Andes and the East African mountains.
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| 2. |
- Alerstam, Thomas, et al.
(författare)
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Flight speeds among bird species : allometric and phylogenetic effects.
- 2007
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Ingår i: PLoS biology. - : Public Library of Science (PLoS). - 1544-9173 .- 1545-7885. ; 5:8, s. e197-
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Tidskriftsartikel (refereegranskat)abstract
- Flight speed is expected to increase with mass and wing loading among flying animals and aircraft for fundamental aerodynamic reasons. Assuming geometrical and dynamical similarity, cruising flight speed is predicted to vary as (body mass)(1/6) and (wing loading)(1/2) among bird species. To test these scaling rules and the general importance of mass and wing loading for bird flight speeds, we used tracking radar to measure flapping flight speeds of individuals or flocks of migrating birds visually identified to species as well as their altitude and winds at the altitudes where the birds were flying. Equivalent airspeeds (airspeeds corrected to sea level air density, Ue) of 138 species, ranging 0.01-10 kg in mass, were analysed in relation to biometry and phylogeny. Scaling exponents in relation to mass and wing loading were significantly smaller than predicted (about 0.12 and 0.32, respectively, with similar results for analyses based on species and independent phylogenetic contrasts). These low scaling exponents may be the result of evolutionary restrictions on bird flight-speed range, counteracting too slow flight speeds among species with low wing loading and too fast speeds among species with high wing loading. This compression of speed range is partly attained through geometric differences, with aspect ratio showing a positive relationship with body mass and wing loading, but additional factors are required to fully explain the small scaling exponent of Ue in relation to wing loading. Furthermore, mass and wing loading accounted for only a limited proportion of the variation in Ue. Phylogeny was a powerful factor, in combination with wing loading, to account for the variation in Ue. These results demonstrate that functional flight adaptations and constraints associated with different evolutionary lineages have an important influence on cruising flapping flight speed that goes beyond the general aerodynamic scaling effects of mass and wing loading.
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| 5. |
- Alström, Per, Professor, et al.
(författare)
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Phylogeny and classification of the avian superfamily Sylvioidea
- 2006
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Ingår i: Molecular Phylogenetics and Evolution. - Swedish Museum Nat Hist, Dept Vertebrate Zool, SE-10405 Stockholm, Sweden. Swedish Museum Nat Hist, Mol Systemat Lab, SE-10405 Stockholm, Sweden. Uppsala Univ, Evolutionary Biol Ctr, Dept Systemat Zool, SE-75236 Uppsala, Sweden. Univ Gothenburg, Dept Zool, SE-40530 Gothenburg, Sweden. : Elsevier BV. - 1055-7903 .- 1095-9513. ; 38:2, s. 381-397
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Tidskriftsartikel (refereegranskat)abstract
- Sylvioidea is one of the three superfamilies recognized within the largest avian radiation, the parvorder Passerida. In the present study, which is the first taxon-dense analysis of the Sylvioidea based on sequence data (nuclear myoglobin intron II and mitochondrial cytochrome b gene), we investigate the interrelationships among the four "sylvioid" clades found by previous workers, as well as the relationships within the largest of these clades. The nuclear and mitochondrial loci estimate basically the same phylogeny, with minor differences in resolution. The trees based on myoglobin and the combined data identify a strongly supported clade that includes the taxa previously allocated to Sylvioidea, except for Sitta (nuthatches), Certhia (treecreepers), Parus (tits), Remiz (penduline tits), Troglodytes and Campylorhynchus (wrens), Polioptila (gnatcatchers), and Regulus (crests/kinglets); this clade also comprises larks, which have previously been placed in the superfamily Passeroidea. We refer to this clade as Sylvioidea. This clade is further divided into 10 main, well-supported clades, which we suggest form the basis for a revised classification. (c) 2005 Elsevier Inc. All rights reserved.
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| 6. |
- Dalsätt, Johan, 1969-, et al.
(författare)
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Food remains in Confuciusornis sanctus suggest a fish diet.
- 2006
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Ingår i: Die Naturwissenschaften. - : Springer Science and Business Media LLC. - 0028-1042 .- 1432-1904. ; 93:9, s. 444-6
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Tidskriftsartikel (refereegranskat)abstract
- Despite hundreds of excellent fossils of Confuciusornis, the most abundant group of birds in the Early Cretaceous, 'Jehol Biota' in China, there is yet no indication of the food choice of these birds. Here, we describe fish remains preserved in the alimentary system of a specimen of Confuciusornis sanctus from the Jiufotang Formation. This find is about five million years younger than all previously published confuciusornithid birds from the Yixian Formation. Although it is unknown how common fish was in the diet of Confuciusornis, the find does not support previous hypotheses that it fed on plants or grain.
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| 7. |
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| 8. |
- Ekman, Jan, et al.
(författare)
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Out of Gondwanaland; the evolutionary history of cooperative breeding and social behaviour among crows, magpies, jays and allies.
- 2006
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 273:1590, s. 1117-25
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Tidskriftsartikel (refereegranskat)abstract
- Cooperative breeding is comparatively rare among birds in the mainly temperate and boreal Northern Hemisphere. Here we test if the distribution of breeding systems reflects a response to latitude by means of a phylogenetic analysis using correlates with geographical range among the corvids (crows, jays, magpies and allied groups). The corvids trace their ancestry to the predominantly cooperative 'Corvida' branch of oscine passerines from the Australo-Papuan region on the ancient Gondwanaland supercontinent, but we could not confirm the ancestral state of the breeding system within the family, while family cohesion may be ancestral. Initial diversification among pair-breeding taxa that are basal in the corvid phylogeny, represented by genera such as Pyrrhocorax and Dendrocitta, indicates that the corvid family in its current form could have evolved from pair-breeding ancestors only after they had escaped the Australo-Papuan shield. Within the family, cooperative breeding (alloparental care/family cohesion) is strongly correlated to latitude and its predominance in species maintaining a southerly distribution indicates a secondary evolution of cooperative breeding in the lineage leading away from the basal corvids. Multiple transitions show plasticity in the breeding system, indicating a response to latitude rather than evolutionary inertia. The evolutionary background to the loss of cooperative breeding among species with a northerly distribution is complex and differs between species, indicating a response to a variety of selection forces. Family cohesion where the offspring provide alloparental care is a main route to cooperatively breeding groups among corvids. Some corvid species lost only alloparental care, while maintaining coherent family groups. Other species lost family cohesion and, as a corollary, they also lost the behaviour where retained offspring provide alloparental care.
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| 10. |
- Ericson, Per G P, 1956-, et al.
(författare)
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Diversification of Neoaves : integration of molecular sequence data and fossils.
- 2006
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Ingår i: Biology Letters. - : The Royal Society. - 1744-9561 .- 1744-957X. ; 2:4, s. 543-7
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Tidskriftsartikel (refereegranskat)abstract
- Patterns of diversification and timing of evolution within Neoaves, which includes almost 95% of all bird species, are virtually unknown. On the other hand, molecular data consistently indicate a Cretaceous origin of many neoavian lineages and the fossil record seems to support an Early Tertiary diversification. Here, we present the first well-resolved molecular phylogeny for Neoaves, together with divergence time estimates calibrated with a large number of stratigraphically and phylogenetically well-documented fossils. Our study defines several well-supported clades within Neoaves. The calibration results suggest that Neoaves, after an initial split from Galloanseres in Mid-Cretaceous, diversified around or soon after the K/T boundary. Our results thus do not contradict palaeontological data and show that there is no solid molecular evidence for an extensive pre-Tertiary radiation of Neoaves.
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