| 1. |
- Hart Reeve, Andrew, et al.
(författare)
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The formation of the Indo-Pacific montane avifauna
- 2023
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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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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| 2. |
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| 3. |
- Jønsson, Knud Andreas, et al.
(författare)
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Evidence of taxon cycles in an Indo-Pacific passerine bird radiation (Aves: Pachycephala).
- 2014
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 281:1777, s. 20131727-
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Tidskriftsartikel (refereegranskat)abstract
- Many insular taxa possess extraordinary abilities to disperse but may differ in their abilities to diversify and compete. While some taxa are widespread across archipelagos, others have disjunct (relictual) populations. These types of taxa, exemplified in the literature by selections of unrelated taxa, have been interpreted as representing a continuum of expansions and contractions (i.e. taxon cycles). Here, we use molecular data of 35 out of 40 species of the avian genus Pachycephala (including 54 out of 66 taxa in Pachycephala pectoralis (sensu lato), to assess the spatio-temporal evolution of the group. We also include data on species distributions, morphology, habitat and elevational ranges to test a number of predictions associated with the taxon-cycle hypothesis. We demonstrate that relictual species persist on the largest and highest islands across the Indo-Pacific, whereas recent archipelago expansions resulted in colonization of all islands in a region. For co-occurring island taxa, the earliest colonists generally inhabit the interior and highest parts of an island, with little spatial overlap with later colonists. Collectively, our data support the idea that taxa continuously pass through phases of expansions and contractions (i.e. taxon cycles).
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| 4. |
- Jønsson, Knud Andreas, et al.
(författare)
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The evolution of mimicry of friarbirds by orioles (Aves : Passeriformes) in Australo-Pacific archipelagos.
- 2016
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Ingår i: Proceedings of the Royal Society of London. Biological Sciences. - : The Royal Society. - 0962-8452 .- 1471-2954. ; 283:1833
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Tidskriftsartikel (refereegranskat)abstract
- Observations by Alfred Wallace and Jared Diamond of plumage similarities between co-occurring orioles (Oriolus) and friarbirds (Philemon) in the Malay archipelago led them to conclude that the former represent visual mimics of the latter. Here, we use molecular phylogenies and plumage reflectance measurements to test several key predictions of the mimicry hypothesis. We show that friarbirds originated before brown orioles, that the two groups did not co-speciate, although there is one plausible instance of co-speciation among species on the neighbouring Moluccan islands of Buru and Seram. Furthermore, we show that greater size disparity between model and mimic and a longer history of co-occurrence have resulted in a stronger plumage similarity (mimicry). This suggests that resemblance between orioles and friarbirds represents mimicry and that colonization of islands by brown orioles has been facilitated by their ability to mimic the aggressive friarbirds.
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| 5. |
- Pedersen, Michael Pepke, et al.
(författare)
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Phylogeography of a "€˜great speciator"€™ (Aves: Edolisoma tenuirostre) reveals complex dispersal and diversification dynamics across the Indo-Pacific
- 2018
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Ingår i: Journal of Biogeography. - : Wiley-Blackwell. - 0305-0270. ; 45:4, s. 826-837
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Aim We derive a new phylogenetic framework of the Indo-Pacific avian genus Edolisoma based on a dense taxon sampling and use it in an explicit spatiotemporal framework to understand the history of intraspecific diversification dynamics in a ‘great speciator’, the Cicadabird Edolisoma tenuirostre/remotum complex. Location The Indo-Pacific island region, Australia and New Guinea. Taxon Corvoid passerine birds (Passeriformes). Methods We used Bayesian phylogenetic methods (beast) to construct a time-calibrated molecular phylogeny of all 19 species in the genus Edolisoma and 27 of 29 subspecies of the E. tenuirostre/remotum complex (previously Coracina tenuirostris) primarily based on one mitochondrial DNA marker. Ancestral area reconstruction methods (‘BioGeoBEARS’) were used to infer the historical biogeography of the genus. We used population-level analyses to assess intraspecific phylogeography and a molecular species delimitation test to evaluate the current taxonomy. A morphometric dataset was used to discuss differential dispersal ability among taxa. Results Edolisoma originated in the late Miocene and diversification within the E. tenuirostre/remotum complex began in the Pleistocene. Within the North Melanesian and North Wallacean archipelagos, which have experienced several waves of diversification, we find significant patterns of genetic isolation by distance, but not within the Australo-Papuan ‘mainland’, which was recently back-colonized from these archipelagos. Based on the phylogeny, we suggest several taxonomic changes. We also discuss evidence of taxon cycles within Edolisoma based on correlations of species age, elevational ranges and dispersal ability. Main conclusions The biogeographical history and patterns of differentiation between phylogroups within E. tenuirostre support the importance of barriers to gene flow in island systems. Examples of both recent genetic exchange across significant sea barriers and differentiation across much smaller water gaps suggest complex dispersal and diversification dynamics. The capacity for dispersal away from islands, and gradual shifts in dispersal ability in relation to the geographical setting, is supported as important factors in generating a ‘great speciator’.
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| 6. |
- Reeve, Andrew Hart, et al.
(författare)
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Population genomics of the island thrush elucidates one of earth's great archipelagic radiations.
- 2023
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Ingår i: Evolution letters. - 2056-3744. ; 7:1, s. 24-36
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Tidskriftsartikel (refereegranskat)abstract
- Tropical islands are renowned as natural laboratories for evolutionary study. Lineage radiations across tropical archipelagos are ideal systems for investigating how colonization, speciation, and extinction processes shape biodiversity patterns. The expansion of the island thrush across the Indo-Pacific represents one of the largest yet most perplexing island radiations of any songbird species. The island thrush exhibits a complex mosaic of pronounced plumage variation across its range and is arguably the world's most polytypic bird. It is a sedentary species largely restricted to mountain forests, yet it has colonized a vast island region spanning a quarter of the globe. We conducted a comprehensive sampling of island thrush populations and obtained genome-wide SNP data, which we used to reconstruct its phylogeny, population structure, gene flow, and demographic history. The island thrush evolved from migratory Palearctic ancestors and radiated explosively across the Indo-Pacific during the Pleistocene, with numerous instances of gene flow between populations. Its bewildering plumage variation masks a biogeographically intuitive stepping stone colonization path from the Philippines through the Greater Sundas, Wallacea, and New Guinea to Polynesia. The island thrush's success in colonizing Indo-Pacific mountains can be understood in light of its ancestral mobility and adaptation to cool climates; however, shifts in elevational range, degree of plumage variation and apparent dispersal rates in the eastern part of its range raise further intriguing questions about its biology.
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