scholarly journals Correction for Seehausen et al. , Nuclear markers reveal unexpected genetic variation and a Congolese–Nilotic origin of the Lake Victoria cichlid species flock

2003 ◽  
Vol 270 (1533) ◽  
pp. 2637-2638 ◽  
Author(s):  
O. Seehausen ◽  
E. Koetsier ◽  
M. V. Schneider ◽  
L. J. Chapman ◽  
C. A. Chapman ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Lake Victoria ◽  
Species Flock ◽  
Nuclear Markers ◽  
Cichlid Species

scholarly journals Nuclear markers reveal unexpected genetic variation and a Congolese-Nilotic origin of the Lake Victoria cichlid species flock

2003 ◽  
Vol 270 (1511) ◽  
pp. 129-137 ◽  
Author(s):  
Ole Seehausen ◽  
Egbert Koetsier ◽  
Maria Victoria Schneider ◽  
Lauren J. Chapman ◽  
Colin A. Chapman ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Lake Victoria ◽  
Species Flock ◽  
Nuclear Markers ◽  
Cichlid Species

scholarly journals Back to Tanganyika: a case of recent trans-species-flock dispersal in East African haplochromine cichlid fishes

2015 ◽  
Vol 2 (3) ◽  
pp. 140498 ◽  
Author(s):  
Britta S. Meyer ◽  
Adrian Indermaur ◽  
Xenia Ehrensperger ◽  
Bernd Egger ◽  
Gaspard Banyankimbona ◽  
...  
Keyword(s):  
Lake Tanganyika ◽  
Lake Victoria ◽  
Species Flock ◽  
East African ◽  
Cichlid Species ◽  
African Great Lakes ◽  
Cichlid Fishes ◽  
Haplochromine Cichlid ◽  
Lake Victoria Region ◽  
Adaptive Radiations

The species flocks of cichlid fishes in the East African Great Lakes are the largest vertebrate adaptive radiations in the world and illustrious textbook examples of convergent evolution between independent species assemblages. Although recent studies suggest some degrees of genetic exchange between riverine taxa and the lake faunas, not a single cichlid species is known from Lakes Tanganyika, Malawi and Victoria that is derived from the radiation associated with another of these lakes. Here, we report the discovery of a haplochromine cichlid species in Lake Tanganyika, which belongs genetically to the species flock of haplochromines of the Lake Victoria region. The new species colonized Lake Tanganyika only recently, suggesting that faunal exchange across watersheds and, hence, between isolated ichthyofaunas, is more common than previously thought.

scholarly journals Different Sources of Allelic Variation Drove Repeated Color Pattern Divergence in Cichlid Fishes

2020 ◽  
Author(s):  
Sabine Urban ◽  
Alexander Nater ◽  
Axel Meyer ◽  
Claudius F Kratochwil
Keyword(s):  
Genetic Variation ◽  
De Novo ◽  
Allelic Variation ◽  
Lake Victoria ◽  
Cichlid Fish ◽  
Lake Malawi ◽  
Color Pattern ◽  
Species Flock ◽  
De Novo Mutations ◽  
Phenotypic Divergence

Abstract The adaptive radiations of East African cichlid fish in the Great Lakes Victoria, Malawi, and Tanganyika are well known for their diversity and repeatedly evolved phenotypes. Convergent evolution of melanic horizontal stripes has been linked to a single locus harboring the gene agouti-related peptide 2 (agrp2). However, where and when the causal variants underlying this trait evolved and how they drove phenotypic divergence remained unknown. To test the alternative hypotheses of standing genetic variation versus de novo mutations (independently originating in each radiation), we searched for shared signals of genomic divergence at the agrp2 locus. Although we discovered similar signatures of differentiation at the locus level, the haplotypes associated with stripe patterns are surprisingly different. In Lake Malawi, the highest associated alleles are located within and close to the 5′ untranslated region of agrp2 and likely evolved through recent de novo mutations. In the younger Lake Victoria radiation, stripes are associated with two intronic regions overlapping with a previously reported cis-regulatory interval. The origin of these segregating haplotypes predates the Lake Victoria radiation because they are also found in more basal riverine and Lake Kivu species. This suggests that both segregating haplotypes were present as standing genetic variation at the onset of the Lake Victoria adaptive radiation with its more than 500 species and drove phenotypic divergence within the species flock. Therefore, both new (Lake Malawi) and ancient (Lake Victoria) allelic variation at the same locus fueled rapid and convergent phenotypic evolution.

Enzyme Variation in Haplochromine Cichlid Fishes From Lake Victoria

1984 ◽  
Vol 35 (3) ◽  
pp. 469-478 ◽  
Author(s):  
E. Verheyen ◽  
M. Selens ◽  
J. Van Rompaey
Keyword(s):  
Lake Victoria ◽  
Electrophoretic Analysis ◽  
Allozyme Variation ◽  
Species Flock ◽  
Gene Pools ◽  
Muscle Enzymes ◽  
Cichlid Species ◽  
Evolutionary Changes ◽  
Cichlid Species Flocks ◽  
Very High

In the great lakes of Africa, endemism and high rates of speciation are characteristic for some genera within cichlid species flocks. These flocks present novel problems in differentiation and speciation. Much debate has centered around the actual way in which speciation has taken place in the African lakes and in particular whether or not the cichlid flocks provide an example supporting sympatric as opposed to allopatric speciation. To characterize evolutionary changes in some species of the presumed young species flock of Lake Victoria, we studied allozyme variation through electrophoretic analysis of muscle enzymes from 10 haplochromine species. The genetic similarities calculated between the 8 Haplochromis species are very high (genetic identities are all higher than 0.97). Even the monotypic genera Hoplotilapia retrodens and Macropleurodus bicolor are electrophoretically indistinguishable from members of Haplochromis. Based upon the available evidence, the species used here are biologically valid. Therefore it is argued that the very high genetic similarities reported here (and by other authors) are best explained by a very recent separation of the different haplochromine gene pools. This implies that the genetic differences, which did accompany reproductive isolation, involved either regulatory genes or non enzymatic parts of the structural genome. This is in accordance with the accepted views on the dominant factors in cichlid speciation.

scholarly journals Early learning influences species assortative mating preferences in Lake Victoria cichlid fish

2007 ◽  
Vol 3 (2) ◽  
pp. 134-136 ◽  
Author(s):  
Machteld N Verzijden ◽  
Carel ten Cate
Keyword(s):  
Reproductive Isolation ◽  
Assortative Mating ◽  
Lake Victoria ◽  
Cichlid Fish ◽  
Species Flock ◽  
Mating Preferences ◽  
Sexual Imprinting ◽  
Cichlid Species ◽  
Young Females ◽  
Genetic Mechanisms

The Lake Victoria ‘species flock’ of cichlids is puzzling because reproductive isolation often occurs in the absence of substantial ecological differences among species. Theory predicts that this cannot evolve with most genetic mechanisms for mate choice. We provide the first evidence that learning, in the form of sexual imprinting, helps maintain reproductive isolation among closely related cichlid species. Using a cross-fostering experiment, we show that young females develop a sexual preference for males of their foster mothers' species, even reversing species assortative mating preferences. We suggest that learning creates favourable conditions for reproductive isolation to evolve.

Extensive analysis of ORF sequences from two different cichlid species in Lake Victoria provides molecular evidence for a recent radiation event of the Victoria species flock

Gene ◽  
2004 ◽  
Vol 343 (2) ◽  
pp. 263-269 ◽  
Author(s):  
Masakatsu Watanabe ◽  
Naoki Kobayashi ◽  
Tadasu Shin-i ◽  
Tokumasa Horiike ◽  
Yoshio Tateno ◽  
...  
Keyword(s):  
Lake Victoria ◽  
Species Flock ◽  
Molecular Evidence ◽  
Cichlid Species ◽  
Extensive Analysis

scholarly journals Speciation in the Cladophorales species flock of ancient Lake Baikal

2021 ◽  
Author(s):  
◽  
Sergio Diaz Martinez
Keyword(s):  
Population Genetics ◽  
Genetic Variation ◽  
Reproductive Isolation ◽  
Lake Baikal ◽  
Species Delimitation ◽  
Sympatric Speciation ◽  
Species Flock ◽  
Ancient Lake ◽  
Data Set ◽  
Dispersal Abilities

<p>Understanding speciation is one of the great challenges in evolutionary biology as many of the processes involved in speciation, as well as the forces leading to morphological and genetic differentiation, are not fully understood. Three main modes of speciation have been described: allopatric, parapatric and sympatric. Sympatric speciation is the most enigmatic mode because in the absence of physical barriers, disruptive selection, assortative mating and hybridization play central roles in reproductive isolation. Although it is accepted that sympatric speciation is possible, only a few examples of this process exist to date. Another common method of speciation in plants and algae is via polyploidization. Recently, a promising system to study speciation in sympatry was discovered: the endemic Cladophorales species flock in ancient Lake Baikal, Russia. The flock consists of sixteen taxa grouped in four genera: Chaetocladiella, Chaetomorpha, Cladophora and Gemmiphora. In spite of their morphological diversity, recent molecular analyses have shown that this is a monophyletic group with low genetic variation and nested within the morphologically simple genus Rhizoclonium. Due to their high number of species, endemism and sympatric distribution, many interesting questions have arisen such as what processes are involved in speciation, and whether this group might be a novel example of sympatric speciation. In this study, we analysed the population genetics of the endemic Baikalian Cladophorales to infer the processes shaping the evolution of the group. First, a set of microsatellites was designed using high-throughput sequencing data. Second, species delimitation methods based on genetic clustering were performed. Third, the population genetics of three widely distributed species was analysed looking for evidence of panmixia, a common criteria to support sympatric speciation. A total of 11 microsatellites that mostly cross-amplify between most species were obtained. The genotyping revealed that most loci had more than two alleles per individual indicating polyploidy. As such, the analyses required a different approach which consisted in coding the genotypes as ‘allelic phenotypes’, allowing the use of individuals of different ploidy levels in the same data set. The species delimitation of 15 operative morphotaxa and 727 individuals supported reproductive isolation of five morphotaxa and two hypotheses of conspecificity. However, some morphotaxa showed unclear assignments revealing the need of further research to clarify their reproductive limits. Finally, the population genetics of Chaetomorpha moniliformis, Cladophora compacta and Cl. kursanovii revealed patterns of genetic variation and structure that suggest different reproductive strategies and dispersal abilities. This demonstrates that contrasting biological characteristics may arise in closely related lineages: Chaetomorpha moniliformis with dominant asexual reproduction and long dispersal abilities; Cladophora compacta with high genetic diversity, no population structure and likely to reproduce sexually; Cl. kursanovii with a structure congruent with geographic distribution and more restricted dispersal. The results suggest that polyploidy, rather than speciation with gene flow, is the force driving the reproductive isolation and evolution of this flock. Although many questions remain to be studied, this research provides the first insights into the diversification of this Cladophorales species flock and contributes to the understanding of speciation in freshwater algae.</p>

The destruction of an endemic species flock: quantitative data on the decline of the haplochromine cichlids of Lake Victoria

1992 ◽  
Vol 34 (1) ◽  
pp. 1-28 ◽  
Author(s):  
Frans Witte ◽  
Tijs Goldschmidt ◽  
Jan Wanink ◽  
Martien van Oijen ◽  
Kees Goudswaard ◽  
...  
Keyword(s):  
Endemic Species ◽  
Quantitative Data ◽  
Lake Victoria ◽  
Species Flock ◽  
Haplochromine Cichlids
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