ALBERT

Description: Theoretically, divergent selection on sensory systems can cause speciation through sensory drive. However, empirical evidence is rare and incomplete. Here we demonstrate sensory drive speciation within island populations of cichlid fish. We identify the ecological and molecular basis of divergent evolution in the cichlid visual system, demonstrate associated divergence in male colouration and female preferences, and show subsequent differentiation at neutral loci, indicating reproductive isolation. Evidence is replicated in several pairs of sympatric populations and species. Variation in the slope of the environmental gradients explains variation in the progress towards speciation: speciation occurs on all but the steepest gradients. This is the most complete demonstration so far of speciation through sensory drive without geographical isolation. Our results also provide a mechanistic explanation for the collapse of cichlid fish species diversity during the anthropogenic eutrophication of Lake Victoria.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Seehausen, Ole -- Terai, Yohey -- Magalhaes, Isabel S -- Carleton, Karen L -- Mrosso, Hillary D J -- Miyagi, Ryutaro -- van der Sluijs, Inke -- Schneider, Maria V -- Maan, Martine E -- Tachida, Hidenori -- Imai, Hiroo -- Okada, Norihiro -- England -- Nature. 2008 Oct 2;455(7213):620-6. doi: 10.1038/nature07285.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Zoology, University of Bern, Baltzerstr. 6, CH-3012 Bern, Switzerland. ole.seehausen@aqua.unibe.ch〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18833272" target="_blank"〉PubMed〈/a〉

Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Seehausen, Ole -- England -- Nature. 2009 Apr 30;458(7242):1122-3. doi: 10.1038/4581122a.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19407790" target="_blank"〉PubMed〈/a〉

Description: Species diversity can be lost through two different but potentially interacting extinction processes: demographic decline and speciation reversal through introgressive hybridization. To investigate the relative contribution of these processes, we analysed historical and contemporary data of replicate whitefish radiations from 17 pre-alpine European lakes and reconstructed changes in genetic species differentiation through time using historical samples. Here we provide evidence that species diversity evolved in response to ecological opportunity, and that eutrophication, by diminishing this opportunity, has driven extinctions through speciation reversal and demographic decline. Across the radiations, the magnitude of eutrophication explains the pattern of species loss and levels of genetic and functional distinctiveness among remaining species. We argue that extinction by speciation reversal may be more widespread than currently appreciated. Preventing such extinctions will require that conservation efforts not only target existing species but identify and protect the ecological and evolutionary processes that generate and maintain species.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Vonlanthen, P -- Bittner, D -- Hudson, A G -- Young, K A -- Muller, R -- Lundsgaard-Hansen, B -- Roy, D -- Di Piazza, S -- Largiader, C R -- Seehausen, O -- England -- Nature. 2012 Feb 15;482(7385):357-62. doi: 10.1038/nature10824.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22337055" target="_blank"〉PubMed〈/a〉

Description: A fundamental challenge to our understanding of biodiversity is to explain why some groups of species undergo adaptive radiations, diversifying extensively into many and varied species, whereas others do not. Both extrinsic environmental factors (for example, resource availability, climate) and intrinsic lineage-specific traits (for example, behavioural or morphological traits, genetic architecture) influence diversification, but few studies have addressed how such factors interact. Radiations of cichlid fishes in the African Great Lakes provide some of the most dramatic cases of species diversification. However, most cichlid lineages in African lakes have not undergone adaptive radiations. Here we compile data on cichlid colonization and diversification in 46 African lakes, along with lake environmental features and information about the traits of colonizing cichlid lineages, to investigate why adaptive radiation does and does not occur. We find that extrinsic environmental factors related to ecological opportunity and intrinsic lineage-specific traits related to sexual selection both strongly influence whether cichlids radiate. Cichlids are more likely to radiate in deep lakes, in regions with more incident solar radiation and in lakes where there has been more time for diversification. Weak or negative associations between diversification and lake surface area indicate that cichlid speciation is not constrained by area, in contrast to diversification in many terrestrial taxa. Among the suite of intrinsic traits that we investigate, sexual dichromatism, a surrogate for the intensity of sexual selection, is consistently positively associated with diversification. Thus, for cichlids, it is the coincidence between ecological opportunity and sexual selection that best predicts whether adaptive radiation will occur. These findings suggest that adaptive radiation is predictable, but only when species traits and environmental factors are jointly considered.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wagner, Catherine E -- Harmon, Luke J -- Seehausen, Ole -- 5P20RR016448-10/RR/NCRR NIH HHS/ -- 8 P20 GM103397-10/GM/NIGMS NIH HHS/ -- England -- Nature. 2012 Jul 19;487(7407):366-9. doi: 10.1038/nature11144.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Fish Ecology & Evolution, EAWAG Centre for Ecology, Evolution and Biogeochemistry, 6047 Kastanienbaum, Switzerland. catherine.wagner@eawag.ch〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22722840" target="_blank"〉PubMed〈/a〉

Description: Cichlid fishes are famous for large, diverse and replicated adaptive radiations in the Great Lakes of East Africa. To understand the molecular mechanisms underlying cichlid phenotypic diversity, we sequenced the genomes and transcriptomes of five lineages of African cichlids: the Nile tilapia (Oreochromis niloticus), an ancestral lineage with low diversity; and four members of the East African lineage: Neolamprologus brichardi/pulcher (older radiation, Lake Tanganyika), Metriaclima zebra (recent radiation, Lake Malawi), Pundamilia nyererei (very recent radiation, Lake Victoria), and Astatotilapia burtoni (riverine species around Lake Tanganyika). We found an excess of gene duplications in the East African lineage compared to tilapia and other teleosts, an abundance of non-coding element divergence, accelerated coding sequence evolution, expression divergence associated with transposable element insertions, and regulation by novel microRNAs. In addition, we analysed sequence data from sixty individuals representing six closely related species from Lake Victoria, and show genome-wide diversifying selection on coding and regulatory variants, some of which were recruited from ancient polymorphisms. We conclude that a number of molecular mechanisms shaped East African cichlid genomes, and that amassing of standing variation during periods of relaxed purifying selection may have been important in facilitating subsequent evolutionary diversification.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4353498/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4353498/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Brawand, David -- Wagner, Catherine E -- Li, Yang I -- Malinsky, Milan -- Keller, Irene -- Fan, Shaohua -- Simakov, Oleg -- Ng, Alvin Y -- Lim, Zhi Wei -- Bezault, Etienne -- Turner-Maier, Jason -- Johnson, Jeremy -- Alcazar, Rosa -- Noh, Hyun Ji -- Russell, Pamela -- Aken, Bronwen -- Alfoldi, Jessica -- Amemiya, Chris -- Azzouzi, Naoual -- Baroiller, Jean-Francois -- Barloy-Hubler, Frederique -- Berlin, Aaron -- Bloomquist, Ryan -- Carleton, Karen L -- Conte, Matthew A -- D'Cotta, Helena -- Eshel, Orly -- Gaffney, Leslie -- Galibert, Francis -- Gante, Hugo F -- Gnerre, Sante -- Greuter, Lucie -- Guyon, Richard -- Haddad, Natalie S -- Haerty, Wilfried -- Harris, Rayna M -- Hofmann, Hans A -- Hourlier, Thibaut -- Hulata, Gideon -- Jaffe, David B -- Lara, Marcia -- Lee, Alison P -- MacCallum, Iain -- Mwaiko, Salome -- Nikaido, Masato -- Nishihara, Hidenori -- Ozouf-Costaz, Catherine -- Penman, David J -- Przybylski, Dariusz -- Rakotomanga, Michaelle -- Renn, Suzy C P -- Ribeiro, Filipe J -- Ron, Micha -- Salzburger, Walter -- Sanchez-Pulido, Luis -- Santos, M Emilia -- Searle, Steve -- Sharpe, Ted -- Swofford, Ross -- Tan, Frederick J -- Williams, Louise -- Young, Sarah -- Yin, Shuangye -- Okada, Norihiro -- Kocher, Thomas D -- Miska, Eric A -- Lander, Eric S -- Venkatesh, Byrappa -- Fernald, Russell D -- Meyer, Axel -- Ponting, Chris P -- Streelman, J Todd -- Lindblad-Toh, Kerstin -- Seehausen, Ole -- Di Palma, Federica -- 2R01DE019637-04/DE/NIDCR NIH HHS/ -- F30 DE023013/DE/NIDCR NIH HHS/ -- MC_U137761446/Medical Research Council/United Kingdom -- R01 DE019637/DE/NIDCR NIH HHS/ -- R01 NS034950/NS/NINDS NIH HHS/ -- U54 HG002045/HG/NHGRI NIH HHS/ -- Wellcome Trust/United Kingdom -- England -- Nature. 2014 Sep 18;513(7518):375-81. doi: 10.1038/nature13726. Epub 2014 Sep 3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA [2] MRC Functional Genomics Unit, University of Oxford, Oxford OX1 3QX, UK [3]. ; 1] Department of Fish Ecology and Evolution, Eawag Swiss Federal Institute of Aquatic Science and Technology, Center for Ecology, Evolution &Biogeochemistry, CH-6047 Kastanienbaum, Switzerland [2] Division of Aquatic Ecology, Institute of Ecology &Evolution, University of Bern, CH-3012 Bern, Switzerland [3]. ; 1] MRC Functional Genomics Unit, University of Oxford, Oxford OX1 3QX, UK [2]. ; 1] Gurdon Institute, Cambridge CB2 1QN, UK [2] Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK. ; Division of Aquatic Ecology, Institute of Ecology &Evolution, University of Bern, CH-3012 Bern, Switzerland. ; Department of Biology, University of Konstanz, D-78457 Konstanz, Germany. ; 1] Department of Biology, University of Konstanz, D-78457 Konstanz, Germany [2] European Molecular Biology Laboratory, 69117 Heidelberg, Germany. ; Institute of Molecular and Cell Biology, A*STAR, 138673 Singapore. ; Department of Biology, Reed College, Portland, Oregon 97202, USA. ; Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA. ; Biology Department, Stanford University, Stanford, California 94305-5020, USA. ; Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California 91125, USA. ; Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK. ; Benaroya Research Institute at Virginia Mason, Seattle, Washington 98101, USA. ; Institut Genetique et Developpement, CNRS/University of Rennes, 35043 Rennes, France. ; CIRAD, Campus International de Baillarguet, TA B-110/A, 34398 Montpellier cedex 5, France. ; School of Biology, Georgia Institute of Technology, Atlanta, Georgia 30332-0230, USA. ; Department of Biology, University of Maryland, College Park, Maryland 20742, USA. ; Animal Genetics, Institute of Animal Science, ARO, The Volcani Center, Bet-Dagan, 50250 Israel. ; Zoological Institute, University of Basel, CH-4051 Basel, Switzerland. ; 1] Department of Fish Ecology and Evolution, Eawag Swiss Federal Institute of Aquatic Science and Technology, Center for Ecology, Evolution &Biogeochemistry, CH-6047 Kastanienbaum, Switzerland [2] Division of Aquatic Ecology, Institute of Ecology &Evolution, University of Bern, CH-3012 Bern, Switzerland. ; MRC Functional Genomics Unit, University of Oxford, Oxford OX1 3QX, UK. ; Department of Integrative Biology, Center for Computational Biology and Bioinformatics; The University of Texas at Austin, Austin, Texas 78712, USA. ; Department of Fish Ecology and Evolution, Eawag Swiss Federal Institute of Aquatic Science and Technology, Center for Ecology, Evolution &Biogeochemistry, CH-6047 Kastanienbaum, Switzerland. ; Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 226-8501 Yokohama, Japan. ; Systematique, Adaptation, Evolution, National Museum of Natural History, 75005 Paris, France. ; Institute of Aquaculture, University of Stirling, Stirling FK9 4LA, UK. ; Carnegie Institution of Washington, Department of Embryology, 3520 San Martin Drive Baltimore, Maryland 21218, USA. ; 1] Department of Biological Sciences, Tokyo Institute of Technology, Tokyo, 226-8501 Yokohama, Japan [2] National Cheng Kung University, Tainan City, 704 Taiwan. ; Gurdon Institute, Cambridge CB2 1QN, UK. ; 1] Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA [2] Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, 751 23 Uppsala, Sweden. ; 1] Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA [2] Vertebrate and Health Genomics, The Genome Analysis Centre, Norwich NR18 7UH, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/25186727" target="_blank"〉PubMed〈/a〉

Description: Cichlid fishes have evolved tremendous morphological and behavioral diversity in the waters of East Africa. Within each of the Great Lakes Tanganyika, Malawi, and Victoria, the phenomena of hybridization and retention of ancestral polymorphism explain allele sharing across species. Here, we explore the sharing of single nucleotide polymorphisms (SNPs) between the major East African cichlid assemblages. A set of approximately 200 genic and nongenic SNPs was ascertained in five Lake Malawi species and genotyped in a diverse collection of ~160 species from across Africa. We observed segregating polymorphism outside of the Malawi lineage for more than 50% of these loci; this holds similarly for genic versus nongenic SNPs, as well as for SNPs at putative CpG versus non-CpG sites. Bayesian and principal component analyses of genetic structure in the data demonstrate that the Lake Malawi endemic flock is not monophyletic and that river species have likely contributed significantly to Malawi genomes. Coalescent simulations support the hypothesis that river cichlids have transported polymorphism between lake assemblages. We observed strong genetic differentiation between Malawi lineages for approximately 8% of loci, with contributions from both genic and nongenic SNPs. Notably, more than half of these outlier loci between Malawi groups are polymorphic outside of the lake. Cichlid fishes have evolved diversity in Lake Malawi as new mutations combined with standing genetic variation shared across East Africa.

Description: A critical step for speciation in the face of gene flow is the origination of reproductive isolation. The evolution of assortative mating greatly facilitates this process. Assortative mating can be mediated by one or multiple cues across an array of sensory modalities. We here explore possible cues that may underlie female mate choice in a sympatric species pair of cichlid fish from Lake Victoria, Pundamilia pundamilia and Pundamilia nyererei . Previous studies identified species-specific female preferences for male coloration, but effects of other cues could not be ruled out. Therefore, we assessed female choice in a series of experiments in which we manipulated visual (color) and chemical cues. We show that the visibility of differences in nuptial hue (i.e., either blue or red) between males of the 2 species is necessary and sufficient for assortative mating by female mate choice. Such assortment mediated by a single cue may evolve relatively quickly, but could make reproductive isolation vulnerable to environmental changes. These findings confirm the important role of female mate choice for male nuptial hue in promoting the explosive speciation of African haplochromine cichlids.