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Per-arne Amundsen - One of the best experts on this subject based on the ideXlab platform.
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Diversifying selection drives parallel evolution of gill raker number and body size along the speciation continuum of European whitefish
Ecology and Evolution, 2018Co-Authors: Katja Häkli, Kjartan Ostbye, Kimmo K Kahilainen, Per-arne Amundsen, Kim PraebelAbstract:Adaptive radiation is the evolution of ecological and phenotypical diversity. It arises via ecological opportunity that promotes the exploration of underutilized or novel niches mediating specialization and reproductive isolation. The assumed precondition for rapid local adaptation is diversifying natural selection, but random genetic drift could also be a major driver of this process. We used 27 populations of European whitefish (Coregonus lavaretus) from nine lakes distributed in three neighboring subarctic watercourses in northern Fennoscandia as a model to test the importance of random drift versus diversifying natural selection for parallel evolution of adaptive phenotypic traits. We contrasted variation for two key adaptive phenotypic traits correlated with resource utilization of polymorphic fish; the number of gill rakers and the total length of fish, with the posterior distribution of neutral genetic differentiation from 13 microsatellite loci, to test whether the observed phenotypic divergence could be achieved by random genetic drift alone. Our results show that both traits have been under diversifying selection and that the evolution of these morphs has been driven by isolation through habitat adaptations. We conclude that diversifying selection acting on gill raker number and body size has played a significant role in the ongoing adaptive radiation of European whitefish morphs in this region.
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The role of gill raker number variability in adaptive radiation of coregonid fish
Evolutionary Ecology, 2011Co-Authors: Kimmo K Kahilainen, Anna Siwertsson, Rune Knudsen, Karl Ø. Gjelland, Thomas Bøhn, Per-arne AmundsenAbstract:Gill raker divergence is a general pattern in adaptive radiations of postglacial fish, but few studies have addressed the adaptive significance of this morphological trait in foraging and eco-evolutionary interactions among predator and prey. Here, a set of subarctic lakes along a diversifying gradient of coregonids was used as the natural setting to explore correlations between gill raker numbers and planktivory as well as the impact of coregonid radiation on zooplankton communities. Results from 19 populations covering most of the total gill raker number gradient of the genus Coregonus , confirm that the number of gill rakers has a central role in determining the foraging ability towards zooplankton prey. Both at the individual and population levels, gill raker number was correlated with pelagic niche use and the size of utilized zooplankton prey. Furthermore, the average body size and the abundance and diversity of the zooplankton community decreased with the increasing diversity of coregonids. We argue that zooplankton feeding leads to an eco-evolutionary feedback loop that may further shape the gill raker morphology since natural selection intensifies under resource competition for depleted prey communities. Eco-evolutionary interactions may thus have a central role creating and maintaining the divergence of coregonid morphs in postglacial lakes.
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parallel evolution of ecomorphological traits in the european whitefish coregonus lavaretus l species complex during postglacial times
Molecular Ecology, 2006Co-Authors: Kjartan Ostbye, Rune Knudsen, Per-arne Amundsen, Louis Bernatchez, Anders Klemetsen, Roar Kristoffersen, T F Naesje, Kjetil HindarAbstract:The extensive phenotypic polymorphism in the European whitefish has triggered evolutionary research in order to disentangle mechanisms underlying diversification. To illuminate the ecological distinctiveness in polymorphic whitefish, and evaluate taxonomic designations, we studied nine Norwegian lakes in three watercourses, which each harboured pairs of divergent whitefish morphs. We compared the morphology and life history of these morphs, documented the extent of genetic differentiation between them, and contrasted the niche use of sympatric morphs along both the habitat and resource axes. In all cases, sympatric morphs differed in the number of gill rakers, a highly heritable trait related to trophic utilization. Individual growth rate, age and size at maturity, diet and habitat use also differed between morphs within lakes, but were remarkably similar across lakes within the same morph. Microsatellite analyses confirmed for all but one pair that sympatric morphs were significantly genetically different, and that similar morphs from different lakes likely have a polyphyletic origin. These results are most compatible with the process of parallel evolution through recurrent postglacial divergence into pelagic and benthic niches in each of these lakes. We propose that sparsely and densely rakered whitefish sympatric pairs may be a likely case of ecological speciation, mediated in oligotrophic lakes with few trophic competitors.
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Gill raker morphology and feeding ecology of two sympatric morphs of European whitefish (Coregonus lavaretus)
Annales Zoologici Fennici, 2004Co-Authors: Per-arne Amundsen, Thomas Bøhn, Gry H. VagaAbstract:European whitefish is a polymorphic species where different morphs often are identified by differences in their gill raker numbers. Gill rakers may play an important role in food-particle retention, particularly with respect to zooplankton feeding. Possible associations between feeding ecology and gill raker number and morphology were studied in European whitefish in the Pasvik watercourse. The numbers of gill rakers exhibited a bimodal distribution pattern, demonstrating the presence of two sympatric forms, including a sparsely-rakered morph with 18-30 and a densely-rakered morph with 28-42 rakers. The morphology of the gill rakers was correlated to the raker number and exhibited distinct differences between the morphs; sparsely-rakered whitefish having shorter, thicker and less densely packed rakers than the densely-rakered morph. Differences in habitat choice and trophic ecology between the two morphs appeared to be correlated to gill raker number and morphology. Densely-rakered whitefish exhibited a diet dominated by zooplankton and other pelagic prey, whereas the sparsely-rakered morph mainly fed on zoobenthos. Within the morphs, however, the feeding ecology of individual fish was not correlated with number and morphology of the gill rakers. Thus, whereas gill raker number and morphology appear to be a reliable marker for identifying ecologically and genetically different European whitefish morphs, the functional role with respect to the feeding performance of individual fish is less obvious.
Kjartan Ostbye - One of the best experts on this subject based on the ideXlab platform.
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Diversifying selection drives parallel evolution of gill raker number and body size along the speciation continuum of European whitefish
Ecology and Evolution, 2018Co-Authors: Katja Häkli, Kjartan Ostbye, Kimmo K Kahilainen, Per-arne Amundsen, Kim PraebelAbstract:Adaptive radiation is the evolution of ecological and phenotypical diversity. It arises via ecological opportunity that promotes the exploration of underutilized or novel niches mediating specialization and reproductive isolation. The assumed precondition for rapid local adaptation is diversifying natural selection, but random genetic drift could also be a major driver of this process. We used 27 populations of European whitefish (Coregonus lavaretus) from nine lakes distributed in three neighboring subarctic watercourses in northern Fennoscandia as a model to test the importance of random drift versus diversifying natural selection for parallel evolution of adaptive phenotypic traits. We contrasted variation for two key adaptive phenotypic traits correlated with resource utilization of polymorphic fish; the number of gill rakers and the total length of fish, with the posterior distribution of neutral genetic differentiation from 13 microsatellite loci, to test whether the observed phenotypic divergence could be achieved by random genetic drift alone. Our results show that both traits have been under diversifying selection and that the evolution of these morphs has been driven by isolation through habitat adaptations. We conclude that diversifying selection acting on gill raker number and body size has played a significant role in the ongoing adaptive radiation of European whitefish morphs in this region.
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ecological speciation in postglacial european whitefish rapid adaptive radiations into the littoral pelagic and profundal lake habitats
Ecology and Evolution, 2013Co-Authors: Kim Praebel, Anna Siwertsson, Markku Karhunen, Kjartan Ostbye, Stefano Peruzzi, Rune Knudsen, Kimmo K Kahilainen, Otso Ovaskainen, Sveinerik FevoldenAbstract:Understanding how a monophyletic lineage of a species diverges into several adaptive forms has received increased attention in recent years, but the underlying mechanisms in this process are still under debate. Postglacial fishes are excellent model organisms for exploring this process, especially the initial stages of ecological speciation, as postglacial lakes represent replicated discrete environments with variation in available niches. Here, we combine data of niche utilization, trophic morphology, and 17 microsatellite loci to investigate the diversification process of three sympatric European whitefish morphs from three northern Fennoscandian lakes. The morphological divergence in the gill raker number among the whitefish morphs was related to the utilization of different trophic niches and was associated with reproductive isolation within and across lakes. The intralacustrine comparison of whitefish morphs showed that these systems represent two levels of adaptive divergence: (1) a consistent littoral–pelagic resource axis; and (2) a more variable littoral–profundal resource axis. The results also indicate that the profundal whitefish morph has diverged repeatedly from the ancestral littoral whitefish morph in sympatry in two different watercourses. In contrast, all the analyses performed revealed clustering of the pelagic whitefish morphs across lakes suggesting parallel postglacial immigration with the littoral whitefish morph into each lake. Finally, the analyses strongly suggested that the trophic adaptive trait, number of gill rakers, was under diversifying selection in the different whitefish morphs. Together, the results support a complex evolutionary scenario where ecological speciation acts, but where both allopatric (colonization history) and sympatric (within watercourse divergence) processes are involved.
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parallel evolution of ecomorphological traits in the european whitefish coregonus lavaretus l species complex during postglacial times
Molecular Ecology, 2006Co-Authors: Kjartan Ostbye, Rune Knudsen, Per-arne Amundsen, Louis Bernatchez, Anders Klemetsen, Roar Kristoffersen, T F Naesje, Kjetil HindarAbstract:The extensive phenotypic polymorphism in the European whitefish has triggered evolutionary research in order to disentangle mechanisms underlying diversification. To illuminate the ecological distinctiveness in polymorphic whitefish, and evaluate taxonomic designations, we studied nine Norwegian lakes in three watercourses, which each harboured pairs of divergent whitefish morphs. We compared the morphology and life history of these morphs, documented the extent of genetic differentiation between them, and contrasted the niche use of sympatric morphs along both the habitat and resource axes. In all cases, sympatric morphs differed in the number of gill rakers, a highly heritable trait related to trophic utilization. Individual growth rate, age and size at maturity, diet and habitat use also differed between morphs within lakes, but were remarkably similar across lakes within the same morph. Microsatellite analyses confirmed for all but one pair that sympatric morphs were significantly genetically different, and that similar morphs from different lakes likely have a polyphyletic origin. These results are most compatible with the process of parallel evolution through recurrent postglacial divergence into pelagic and benthic niches in each of these lakes. We propose that sparsely and densely rakered whitefish sympatric pairs may be a likely case of ecological speciation, mediated in oligotrophic lakes with few trophic competitors.
Kimmo K Kahilainen - One of the best experts on this subject based on the ideXlab platform.
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Diversifying selection drives parallel evolution of gill raker number and body size along the speciation continuum of European whitefish
Ecology and Evolution, 2018Co-Authors: Katja Häkli, Kjartan Ostbye, Kimmo K Kahilainen, Per-arne Amundsen, Kim PraebelAbstract:Adaptive radiation is the evolution of ecological and phenotypical diversity. It arises via ecological opportunity that promotes the exploration of underutilized or novel niches mediating specialization and reproductive isolation. The assumed precondition for rapid local adaptation is diversifying natural selection, but random genetic drift could also be a major driver of this process. We used 27 populations of European whitefish (Coregonus lavaretus) from nine lakes distributed in three neighboring subarctic watercourses in northern Fennoscandia as a model to test the importance of random drift versus diversifying natural selection for parallel evolution of adaptive phenotypic traits. We contrasted variation for two key adaptive phenotypic traits correlated with resource utilization of polymorphic fish; the number of gill rakers and the total length of fish, with the posterior distribution of neutral genetic differentiation from 13 microsatellite loci, to test whether the observed phenotypic divergence could be achieved by random genetic drift alone. Our results show that both traits have been under diversifying selection and that the evolution of these morphs has been driven by isolation through habitat adaptations. We conclude that diversifying selection acting on gill raker number and body size has played a significant role in the ongoing adaptive radiation of European whitefish morphs in this region.
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ecological speciation in postglacial european whitefish rapid adaptive radiations into the littoral pelagic and profundal lake habitats
Ecology and Evolution, 2013Co-Authors: Kim Praebel, Anna Siwertsson, Markku Karhunen, Kjartan Ostbye, Stefano Peruzzi, Rune Knudsen, Kimmo K Kahilainen, Otso Ovaskainen, Sveinerik FevoldenAbstract:Understanding how a monophyletic lineage of a species diverges into several adaptive forms has received increased attention in recent years, but the underlying mechanisms in this process are still under debate. Postglacial fishes are excellent model organisms for exploring this process, especially the initial stages of ecological speciation, as postglacial lakes represent replicated discrete environments with variation in available niches. Here, we combine data of niche utilization, trophic morphology, and 17 microsatellite loci to investigate the diversification process of three sympatric European whitefish morphs from three northern Fennoscandian lakes. The morphological divergence in the gill raker number among the whitefish morphs was related to the utilization of different trophic niches and was associated with reproductive isolation within and across lakes. The intralacustrine comparison of whitefish morphs showed that these systems represent two levels of adaptive divergence: (1) a consistent littoral–pelagic resource axis; and (2) a more variable littoral–profundal resource axis. The results also indicate that the profundal whitefish morph has diverged repeatedly from the ancestral littoral whitefish morph in sympatry in two different watercourses. In contrast, all the analyses performed revealed clustering of the pelagic whitefish morphs across lakes suggesting parallel postglacial immigration with the littoral whitefish morph into each lake. Finally, the analyses strongly suggested that the trophic adaptive trait, number of gill rakers, was under diversifying selection in the different whitefish morphs. Together, the results support a complex evolutionary scenario where ecological speciation acts, but where both allopatric (colonization history) and sympatric (within watercourse divergence) processes are involved.
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The role of gill raker number variability in adaptive radiation of coregonid fish
Evolutionary Ecology, 2011Co-Authors: Kimmo K Kahilainen, Anna Siwertsson, Rune Knudsen, Karl Ø. Gjelland, Thomas Bøhn, Per-arne AmundsenAbstract:Gill raker divergence is a general pattern in adaptive radiations of postglacial fish, but few studies have addressed the adaptive significance of this morphological trait in foraging and eco-evolutionary interactions among predator and prey. Here, a set of subarctic lakes along a diversifying gradient of coregonids was used as the natural setting to explore correlations between gill raker numbers and planktivory as well as the impact of coregonid radiation on zooplankton communities. Results from 19 populations covering most of the total gill raker number gradient of the genus Coregonus , confirm that the number of gill rakers has a central role in determining the foraging ability towards zooplankton prey. Both at the individual and population levels, gill raker number was correlated with pelagic niche use and the size of utilized zooplankton prey. Furthermore, the average body size and the abundance and diversity of the zooplankton community decreased with the increasing diversity of coregonids. We argue that zooplankton feeding leads to an eco-evolutionary feedback loop that may further shape the gill raker morphology since natural selection intensifies under resource competition for depleted prey communities. Eco-evolutionary interactions may thus have a central role creating and maintaining the divergence of coregonid morphs in postglacial lakes.
Rune Knudsen - One of the best experts on this subject based on the ideXlab platform.
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ecological speciation in postglacial european whitefish rapid adaptive radiations into the littoral pelagic and profundal lake habitats
Ecology and Evolution, 2013Co-Authors: Kim Praebel, Anna Siwertsson, Markku Karhunen, Kjartan Ostbye, Stefano Peruzzi, Rune Knudsen, Kimmo K Kahilainen, Otso Ovaskainen, Sveinerik FevoldenAbstract:Understanding how a monophyletic lineage of a species diverges into several adaptive forms has received increased attention in recent years, but the underlying mechanisms in this process are still under debate. Postglacial fishes are excellent model organisms for exploring this process, especially the initial stages of ecological speciation, as postglacial lakes represent replicated discrete environments with variation in available niches. Here, we combine data of niche utilization, trophic morphology, and 17 microsatellite loci to investigate the diversification process of three sympatric European whitefish morphs from three northern Fennoscandian lakes. The morphological divergence in the gill raker number among the whitefish morphs was related to the utilization of different trophic niches and was associated with reproductive isolation within and across lakes. The intralacustrine comparison of whitefish morphs showed that these systems represent two levels of adaptive divergence: (1) a consistent littoral–pelagic resource axis; and (2) a more variable littoral–profundal resource axis. The results also indicate that the profundal whitefish morph has diverged repeatedly from the ancestral littoral whitefish morph in sympatry in two different watercourses. In contrast, all the analyses performed revealed clustering of the pelagic whitefish morphs across lakes suggesting parallel postglacial immigration with the littoral whitefish morph into each lake. Finally, the analyses strongly suggested that the trophic adaptive trait, number of gill rakers, was under diversifying selection in the different whitefish morphs. Together, the results support a complex evolutionary scenario where ecological speciation acts, but where both allopatric (colonization history) and sympatric (within watercourse divergence) processes are involved.
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The role of gill raker number variability in adaptive radiation of coregonid fish
Evolutionary Ecology, 2011Co-Authors: Kimmo K Kahilainen, Anna Siwertsson, Rune Knudsen, Karl Ø. Gjelland, Thomas Bøhn, Per-arne AmundsenAbstract:Gill raker divergence is a general pattern in adaptive radiations of postglacial fish, but few studies have addressed the adaptive significance of this morphological trait in foraging and eco-evolutionary interactions among predator and prey. Here, a set of subarctic lakes along a diversifying gradient of coregonids was used as the natural setting to explore correlations between gill raker numbers and planktivory as well as the impact of coregonid radiation on zooplankton communities. Results from 19 populations covering most of the total gill raker number gradient of the genus Coregonus , confirm that the number of gill rakers has a central role in determining the foraging ability towards zooplankton prey. Both at the individual and population levels, gill raker number was correlated with pelagic niche use and the size of utilized zooplankton prey. Furthermore, the average body size and the abundance and diversity of the zooplankton community decreased with the increasing diversity of coregonids. We argue that zooplankton feeding leads to an eco-evolutionary feedback loop that may further shape the gill raker morphology since natural selection intensifies under resource competition for depleted prey communities. Eco-evolutionary interactions may thus have a central role creating and maintaining the divergence of coregonid morphs in postglacial lakes.
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parallel evolution of ecomorphological traits in the european whitefish coregonus lavaretus l species complex during postglacial times
Molecular Ecology, 2006Co-Authors: Kjartan Ostbye, Rune Knudsen, Per-arne Amundsen, Louis Bernatchez, Anders Klemetsen, Roar Kristoffersen, T F Naesje, Kjetil HindarAbstract:The extensive phenotypic polymorphism in the European whitefish has triggered evolutionary research in order to disentangle mechanisms underlying diversification. To illuminate the ecological distinctiveness in polymorphic whitefish, and evaluate taxonomic designations, we studied nine Norwegian lakes in three watercourses, which each harboured pairs of divergent whitefish morphs. We compared the morphology and life history of these morphs, documented the extent of genetic differentiation between them, and contrasted the niche use of sympatric morphs along both the habitat and resource axes. In all cases, sympatric morphs differed in the number of gill rakers, a highly heritable trait related to trophic utilization. Individual growth rate, age and size at maturity, diet and habitat use also differed between morphs within lakes, but were remarkably similar across lakes within the same morph. Microsatellite analyses confirmed for all but one pair that sympatric morphs were significantly genetically different, and that similar morphs from different lakes likely have a polyphyletic origin. These results are most compatible with the process of parallel evolution through recurrent postglacial divergence into pelagic and benthic niches in each of these lakes. We propose that sparsely and densely rakered whitefish sympatric pairs may be a likely case of ecological speciation, mediated in oligotrophic lakes with few trophic competitors.
Kim Praebel - One of the best experts on this subject based on the ideXlab platform.
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Diversifying selection drives parallel evolution of gill raker number and body size along the speciation continuum of European whitefish
Ecology and Evolution, 2018Co-Authors: Katja Häkli, Kjartan Ostbye, Kimmo K Kahilainen, Per-arne Amundsen, Kim PraebelAbstract:Adaptive radiation is the evolution of ecological and phenotypical diversity. It arises via ecological opportunity that promotes the exploration of underutilized or novel niches mediating specialization and reproductive isolation. The assumed precondition for rapid local adaptation is diversifying natural selection, but random genetic drift could also be a major driver of this process. We used 27 populations of European whitefish (Coregonus lavaretus) from nine lakes distributed in three neighboring subarctic watercourses in northern Fennoscandia as a model to test the importance of random drift versus diversifying natural selection for parallel evolution of adaptive phenotypic traits. We contrasted variation for two key adaptive phenotypic traits correlated with resource utilization of polymorphic fish; the number of gill rakers and the total length of fish, with the posterior distribution of neutral genetic differentiation from 13 microsatellite loci, to test whether the observed phenotypic divergence could be achieved by random genetic drift alone. Our results show that both traits have been under diversifying selection and that the evolution of these morphs has been driven by isolation through habitat adaptations. We conclude that diversifying selection acting on gill raker number and body size has played a significant role in the ongoing adaptive radiation of European whitefish morphs in this region.
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ecological speciation in postglacial european whitefish rapid adaptive radiations into the littoral pelagic and profundal lake habitats
Ecology and Evolution, 2013Co-Authors: Kim Praebel, Anna Siwertsson, Markku Karhunen, Kjartan Ostbye, Stefano Peruzzi, Rune Knudsen, Kimmo K Kahilainen, Otso Ovaskainen, Sveinerik FevoldenAbstract:Understanding how a monophyletic lineage of a species diverges into several adaptive forms has received increased attention in recent years, but the underlying mechanisms in this process are still under debate. Postglacial fishes are excellent model organisms for exploring this process, especially the initial stages of ecological speciation, as postglacial lakes represent replicated discrete environments with variation in available niches. Here, we combine data of niche utilization, trophic morphology, and 17 microsatellite loci to investigate the diversification process of three sympatric European whitefish morphs from three northern Fennoscandian lakes. The morphological divergence in the gill raker number among the whitefish morphs was related to the utilization of different trophic niches and was associated with reproductive isolation within and across lakes. The intralacustrine comparison of whitefish morphs showed that these systems represent two levels of adaptive divergence: (1) a consistent littoral–pelagic resource axis; and (2) a more variable littoral–profundal resource axis. The results also indicate that the profundal whitefish morph has diverged repeatedly from the ancestral littoral whitefish morph in sympatry in two different watercourses. In contrast, all the analyses performed revealed clustering of the pelagic whitefish morphs across lakes suggesting parallel postglacial immigration with the littoral whitefish morph into each lake. Finally, the analyses strongly suggested that the trophic adaptive trait, number of gill rakers, was under diversifying selection in the different whitefish morphs. Together, the results support a complex evolutionary scenario where ecological speciation acts, but where both allopatric (colonization history) and sympatric (within watercourse divergence) processes are involved.
