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Ole Seehausen - One of the best experts on this subject based on the ideXlab platform.
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correction for seehausen et al nuclear markers reveal unexpected genetic variation and a congolese nilotic origin of the lake victoria cichlid Species Flock
2003Co-Authors: Ole Seehausen, George F Turner, Egbert Koetsier, Maria Victoria Schneider, Lauren J Chapman, Colin A Chapman, Mairi E Knight, J J M Van Alphen, Roger BillsAbstract:Correction for ‘Nuclear markers reveal unexpected genetic variation and a Congolese–Nilotic origin of the Lake Victoria cichlid Species Flock’ by O. Seehausen, E. Koetsier, M. V. Schneider, L. J. Chapman, C. A. Chapman, M. E. Knight, G. F. Turner, J. J. M. van Alphen and R. Bills (Proc. R. Soc. Lond. B 270 , 129–137. (doi: 10.1098/rspb.2002.2153)). On page 133, in figure 1 several taxon names were misspelled. A list of the incorrect and correct names is given below.
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nuclear markers reveal unexpected genetic variation and a congolese nilotic origin of the lake victoria cichlid Species Flock
2003Co-Authors: Ole Seehausen, Egbert Koetsier, Maria Victoria Schneider, Lauren J Chapman, Colin A Chapman, Mairi E Knight, George F TurnerAbstract:Phylogenetic analyses based on mitochondrial (mt) DNA have indicated that the cichlid Species Flock of the Lake Victoria region is derived from a single ancestral Species found in East African rivers, closely related to the ancestor of the Lake Malawi cichlid Species Flock. The Lake Victoria Flock contains ten times less mtDNA variation than the Lake Malawi radiation, consistent with current estimates of the ages of the lakes. We present results of a phylogenetic investigation using nuclear (amplified fragment length polymorphism) markers and a wider coverage of riverine haplochromines. We demonstrate that the Lake Victoria-Edward Flock is derived from the morphologically and ecologically diverse cichlid genus Thoracochromis from the Congo and Nile, rather than from the phenotypically conservative East African Astatotilapia. This implies that the ability to express much of the morphological diversity found in the Species Flock may by far pre-date the origin of the Flock. Our data indicate that the nuclear diversity of the Lake Victoria-Edward Species Flock is similar to that of the Lake Malawi Flock, indicating that the genetic diversity is considerably older than the 15 000 years that have passed since the lake began to refill. Most of this variation is manifested in trans-Species polymorphisms, indicating very recent cladogenesis from a genetically very diverse founder stock. Our data do not confirm strict monophyly of either of the Species Flocks, but raise the possibility that these Flocks have arisen from hybrid swarms.
George F Turner - One of the best experts on this subject based on the ideXlab platform.
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female preference for conspecific males based on olfactory cues in a lake malawi cichlid fish
2005Co-Authors: Martin Plenderleith, Cock Van Oosterhout, Rosanna L Robinson, George F TurnerAbstract:Research on reproductive isolation in African cichlid fishes has largely focused on the role of nuptial colours, but other sensory modes may play an important role in mate choice. Here, we compare the relative importance of visual and olfactory cues in mate recognition by females of a Lake Malawi cichlid Species. Female Pseudotropheus emmiltos were given a choice of spawning next to a conspecific male or a male of the closely-related sympatric Pseudotropheus fainzilberi. Significant preference for conspecific males only occurred when olfactory cues were present. This suggests that divergence of olfactory signals may have been an important influence on the explosive radiation of the East African Species Flock.
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correction for seehausen et al nuclear markers reveal unexpected genetic variation and a congolese nilotic origin of the lake victoria cichlid Species Flock
2003Co-Authors: Ole Seehausen, George F Turner, Egbert Koetsier, Maria Victoria Schneider, Lauren J Chapman, Colin A Chapman, Mairi E Knight, J J M Van Alphen, Roger BillsAbstract:Correction for ‘Nuclear markers reveal unexpected genetic variation and a Congolese–Nilotic origin of the Lake Victoria cichlid Species Flock’ by O. Seehausen, E. Koetsier, M. V. Schneider, L. J. Chapman, C. A. Chapman, M. E. Knight, G. F. Turner, J. J. M. van Alphen and R. Bills (Proc. R. Soc. Lond. B 270 , 129–137. (doi: 10.1098/rspb.2002.2153)). On page 133, in figure 1 several taxon names were misspelled. A list of the incorrect and correct names is given below.
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nuclear markers reveal unexpected genetic variation and a congolese nilotic origin of the lake victoria cichlid Species Flock
2003Co-Authors: Ole Seehausen, Egbert Koetsier, Maria Victoria Schneider, Lauren J Chapman, Colin A Chapman, Mairi E Knight, George F TurnerAbstract:Phylogenetic analyses based on mitochondrial (mt) DNA have indicated that the cichlid Species Flock of the Lake Victoria region is derived from a single ancestral Species found in East African rivers, closely related to the ancestor of the Lake Malawi cichlid Species Flock. The Lake Victoria Flock contains ten times less mtDNA variation than the Lake Malawi radiation, consistent with current estimates of the ages of the lakes. We present results of a phylogenetic investigation using nuclear (amplified fragment length polymorphism) markers and a wider coverage of riverine haplochromines. We demonstrate that the Lake Victoria-Edward Flock is derived from the morphologically and ecologically diverse cichlid genus Thoracochromis from the Congo and Nile, rather than from the phenotypically conservative East African Astatotilapia. This implies that the ability to express much of the morphological diversity found in the Species Flock may by far pre-date the origin of the Flock. Our data indicate that the nuclear diversity of the Lake Victoria-Edward Species Flock is similar to that of the Lake Malawi Flock, indicating that the genetic diversity is considerably older than the 15 000 years that have passed since the lake began to refill. Most of this variation is manifested in trans-Species polymorphisms, indicating very recent cladogenesis from a genetically very diverse founder stock. Our data do not confirm strict monophyly of either of the Species Flocks, but raise the possibility that these Flocks have arisen from hybrid swarms.
Ulrike Strecker - One of the best experts on this subject based on the ideXlab platform.
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behavioral diversification in a young Species Flock of pupfish cyprionodon spp shoaling and aggressive behavior
2008Co-Authors: Martin Plath, Ulrike StreckerAbstract:Increasing empirical and theoretical evidence supports the idea that sympatric speciation is operating, for example, in Species Flocks comprising several closely related fish Species within one lake. Divergent natural selection (promoting spatial and food niche partitioning) and sexual selection (assortative mating) have been identified as key selection factors in intralacustric adaptive radiations. However, the evolution of social behaviors accompanying such adaptive radiations is less well understood. Using a phylogenetically young Species Flock of pupfish (Cyprinodon spp.) as a model, we examined differences among six sympatric Species and compared their shoaling, aggressive, and territorial behaviors with that of a sister Species (C. artifrons). Despite an estimated age of the Species Flock of less than 8,000 years, pronounced behavioral differentiation was found. C. simus, the smallest Species in the Flock, shoaled more than the other Species and was less aggressive and less territorial than C. beltrani. F1-hybrids between C. simus males and C. beltrani females showed an intermediate expression of shoaling and aggressive behavior. Niche partitioning among the members of this Species Flock appears to be accompanied by rapid divergent evolution of social behaviors. We discuss the potential role of phenotypic plasticity and within-Species variation of social behaviors for such rapid behavioral diversifications in sympatric speciation processes.
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characterization and cross Species amplification of microsatellite loci in a cyprinodon Species Flock
2006Co-Authors: Ulrike StreckerAbstract:In this study, two new microsatellite loci from a library of Cyprinodon beltrani from Laguna Chichancanab, Mexico, were characterized. Additionally, cross-Species amplification with primer pairs developed for other Cyprinodon Species was performed. The 11 markers show moderate to high levels of polymorphism (two to 33 alleles) in six Species of the Cyprinodon Flock from Laguna Chichancanab and in their sister Species Cyprinodon artifrons. These loci were characterized for population genetic study to detect gene flow between the different endemic pupfish Species.
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Genetic differentiation and reproductive isolation in a Cyprinodon fish Species Flock from Laguna Chichancanab, Mexico.
2006Co-Authors: Ulrike StreckerAbstract:The Cyprinodon Species Flock from Laguna Chichancanab, aged 8000 years, provides another potential case of sympatric speciation. The Flock consists of seven morphologically distinct Species, each within partially different trophic niches, and a group of specimens which cannot unequivocally be assigned to one of these Species. Genetic analyses, based on mtDNA and five microsatellite loci, revealed significant genetic differentiation of one Species, C. maya, from other members of the Species Flock, providing strong evidence for reproductive isolation. For the remaining members of the Flock significant genetic structuring was detected, with some evidence of gene flow with the most abundant Species C. beltrani. These analyses suggest that speciation proceeds with ongoing hybridisation, and further suggest that the morphologically unidentifiable specimens found in the lake are probably hybrids. I propose that in the Cyprinodon Species Flock besides disruptive selection sexual selection plays an important part in achieving and maintaining reproductive isolation.
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description of a new Species from laguna chichancanab yucatan mexico cyprinodon suavium pisces cyprinodontidae
2005Co-Authors: Ulrike StreckerAbstract:Cyprinodon suavium is a new Species that belongs to the endemic Species Flock from Laguna Chichancanab, Yucatan, Mexico, which is proposed to have evolved by sympatric speciation in the lake during the last 8000 years. C. suaviumis distinguished from all other known Cyprinodon Species by a flattened and concave inter- and postorbital skull roof and a terminal mouth with distinctive thickened lips. The short gut length and dietary items found in the gut indicate that C. suavium is one of the carnivorous members of the Flock.
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trophic differentiation in the phylogenetically young cyprinodon Species Flock cyprinodontidae teleostei from laguna chichancanab mexico
2005Co-Authors: Joachim Horstkotte, Ulrike StreckerAbstract:Analysis of the gut contents of six syntopic Cyprinodon Species from Laguna Chichancanab, Mexico, shows that the supposed basal form, C. beltrani, feeds on detritus and has the longest gut. All other Species have significantly shorter guts. Whereas C. simus exclusively ingests detritus despite short gut length, all other Species additionally rely on different benthic invertebrates. Each Species has developed specific preferences: C. labiosus (amphipods), C. verecundus (bivalves), C. maya (ostracods and gastropods) and C. esconditus (ostracods and chironomid larvae). However, all of them ingest a minimum of c. 40% detritus. According to Schoener's index, pairwise niche overlap varies from c. 40% to over 95% in the Species Flock. Contrary to this, there is almost no overlap between the members of the Flock and the only other native fish Species, Gambusia sexradiata, which feeds nearly exclusively on terrestrial arthropods dropping on the water surface. Recently, the cichlid genus Oreochromis and the characid Astyanax fasciatus gained access to the lake. The cichlids show moderate to high niche overlap, whereas in A. fasciatus it is low. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 85, 125–134.
Colin A Chapman - One of the best experts on this subject based on the ideXlab platform.
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correction for seehausen et al nuclear markers reveal unexpected genetic variation and a congolese nilotic origin of the lake victoria cichlid Species Flock
2003Co-Authors: Ole Seehausen, George F Turner, Egbert Koetsier, Maria Victoria Schneider, Lauren J Chapman, Colin A Chapman, Mairi E Knight, J J M Van Alphen, Roger BillsAbstract:Correction for ‘Nuclear markers reveal unexpected genetic variation and a Congolese–Nilotic origin of the Lake Victoria cichlid Species Flock’ by O. Seehausen, E. Koetsier, M. V. Schneider, L. J. Chapman, C. A. Chapman, M. E. Knight, G. F. Turner, J. J. M. van Alphen and R. Bills (Proc. R. Soc. Lond. B 270 , 129–137. (doi: 10.1098/rspb.2002.2153)). On page 133, in figure 1 several taxon names were misspelled. A list of the incorrect and correct names is given below.
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nuclear markers reveal unexpected genetic variation and a congolese nilotic origin of the lake victoria cichlid Species Flock
2003Co-Authors: Ole Seehausen, Egbert Koetsier, Maria Victoria Schneider, Lauren J Chapman, Colin A Chapman, Mairi E Knight, George F TurnerAbstract:Phylogenetic analyses based on mitochondrial (mt) DNA have indicated that the cichlid Species Flock of the Lake Victoria region is derived from a single ancestral Species found in East African rivers, closely related to the ancestor of the Lake Malawi cichlid Species Flock. The Lake Victoria Flock contains ten times less mtDNA variation than the Lake Malawi radiation, consistent with current estimates of the ages of the lakes. We present results of a phylogenetic investigation using nuclear (amplified fragment length polymorphism) markers and a wider coverage of riverine haplochromines. We demonstrate that the Lake Victoria-Edward Flock is derived from the morphologically and ecologically diverse cichlid genus Thoracochromis from the Congo and Nile, rather than from the phenotypically conservative East African Astatotilapia. This implies that the ability to express much of the morphological diversity found in the Species Flock may by far pre-date the origin of the Flock. Our data indicate that the nuclear diversity of the Lake Victoria-Edward Species Flock is similar to that of the Lake Malawi Flock, indicating that the genetic diversity is considerably older than the 15 000 years that have passed since the lake began to refill. Most of this variation is manifested in trans-Species polymorphisms, indicating very recent cladogenesis from a genetically very diverse founder stock. Our data do not confirm strict monophyly of either of the Species Flocks, but raise the possibility that these Flocks have arisen from hybrid swarms.
Lauren J Chapman - One of the best experts on this subject based on the ideXlab platform.
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correction for seehausen et al nuclear markers reveal unexpected genetic variation and a congolese nilotic origin of the lake victoria cichlid Species Flock
2003Co-Authors: Ole Seehausen, George F Turner, Egbert Koetsier, Maria Victoria Schneider, Lauren J Chapman, Colin A Chapman, Mairi E Knight, J J M Van Alphen, Roger BillsAbstract:Correction for ‘Nuclear markers reveal unexpected genetic variation and a Congolese–Nilotic origin of the Lake Victoria cichlid Species Flock’ by O. Seehausen, E. Koetsier, M. V. Schneider, L. J. Chapman, C. A. Chapman, M. E. Knight, G. F. Turner, J. J. M. van Alphen and R. Bills (Proc. R. Soc. Lond. B 270 , 129–137. (doi: 10.1098/rspb.2002.2153)). On page 133, in figure 1 several taxon names were misspelled. A list of the incorrect and correct names is given below.
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nuclear markers reveal unexpected genetic variation and a congolese nilotic origin of the lake victoria cichlid Species Flock
2003Co-Authors: Ole Seehausen, Egbert Koetsier, Maria Victoria Schneider, Lauren J Chapman, Colin A Chapman, Mairi E Knight, George F TurnerAbstract:Phylogenetic analyses based on mitochondrial (mt) DNA have indicated that the cichlid Species Flock of the Lake Victoria region is derived from a single ancestral Species found in East African rivers, closely related to the ancestor of the Lake Malawi cichlid Species Flock. The Lake Victoria Flock contains ten times less mtDNA variation than the Lake Malawi radiation, consistent with current estimates of the ages of the lakes. We present results of a phylogenetic investigation using nuclear (amplified fragment length polymorphism) markers and a wider coverage of riverine haplochromines. We demonstrate that the Lake Victoria-Edward Flock is derived from the morphologically and ecologically diverse cichlid genus Thoracochromis from the Congo and Nile, rather than from the phenotypically conservative East African Astatotilapia. This implies that the ability to express much of the morphological diversity found in the Species Flock may by far pre-date the origin of the Flock. Our data indicate that the nuclear diversity of the Lake Victoria-Edward Species Flock is similar to that of the Lake Malawi Flock, indicating that the genetic diversity is considerably older than the 15 000 years that have passed since the lake began to refill. Most of this variation is manifested in trans-Species polymorphisms, indicating very recent cladogenesis from a genetically very diverse founder stock. Our data do not confirm strict monophyly of either of the Species Flocks, but raise the possibility that these Flocks have arisen from hybrid swarms.
