Ancient hybridization fuels rapid cichlid fish adaptive radiations
Joana I. Meier, David A. Marques, Salome Mwaiko, Catherine E. Wagner, Laurent Excoffier & Ole Seehausen
Nature Communications 8, Article number: 14363 (2017)
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Adaptive radiation Evolutionary genetics Molecular evolution Phylogenetics
Received: 14 May 2016 Accepted: 20 December 2016 Published online: 10 February 2017
Abstract
Understanding why some evolutionary lineages generate exceptionally high species diversity is an important goal in evolutionary biology. Haplochromine cichlid fishes of Africa’s Lake Victoria region encompass >700 diverse species that all evolved in the last 150,000 years. How this ‘Lake Victoria Region Superflock’ could evolve on such rapid timescales is an enduring question. Here, we demonstrate that hybridization between two divergent lineages facilitated this process by providing genetic variation that subsequently became recombined and sorted into many new species. Notably, the hybridization event generated exceptional allelic variation at an opsin gene known to be involved in adaptation and speciation. More generally, differentiation between new species is accentuated around variants that were fixed differences between the parental lineages, and that now appear in many new combinations in the radiation species. We conclude that hybridization between divergent lineages, when coincident with ecological opportunity, may facilitate rapid and extensive adaptive radiation.
Acknowledgements
We thank all collaborators who provided tissue samples over the years: Sigal Balshine-Earn (McMaster), Roger Bills (SAIAB), Julia Day (UCL), Yves Fermon (Paris), John Friel (CUMV), Martin Genner (U Bristol), Sylvain Piry (Paris), Lukas Rüber (Bern Natural History Museum), Walter Salzburger (U Basel), Uli Schliewen (Zoologische Staatssammlung Munich), Erwin Schraml (Augsburg), Jos Snoeks (Africa Museum Tervuren), Melanie Stiassny (AMNH), George Turner (U Bangor), Sylvester Wandera (NAFIRI; Uganda) and Marco Welss (Kressberg). We also thank Matt McGee for help with DNA extraction, Keith Harshman of the Lausanne Genomic Technologies Facility and Cord Drogemüller, Tosso Leeb, Muriel Fragnière and Michèle Ackermann of the NGS platform of the University of Bern for Illumina sequencing support, Aria Minder and Stefan Zoller of the Genetic Diversity Center (GDC) at ETH Zürich and Irene Keller of the Interfaculty Bioinformatics Unit at the University of Bern for lab and bioinformatics support and discussion, and Andy Cohen for comments on the paleogeographic maps. This research was supported by the Swiss National Science Foundation grant PDFMP3 134657 to O.S. and L.E.
Author information
Affiliations
Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, 3012 Bern, Switzerland
Joana I. Meier, David A. Marques, Salome Mwaiko, Catherine E. Wagner & Ole Seehausen
Department of Fish Ecology and Evolution, Centre for Ecology, Evolution & Biogeochemistry, Eawag: Swiss Federal Institute of Aquatic Science and Technology, 6047 Kastanienbaum, Switzerland
Joana I. Meier, David A. Marques, Salome Mwaiko, Catherine E. Wagner & Ole Seehausen
Computational and Molecular Population Genetics Lab, Institute of Ecology and Evolution, University of Bern, 3012 Bern, Switzerland
Joana I. Meier, David A. Marques & Laurent Excoffier
Biodiversity Institute & Department of Botany, University of Wyoming, Laramie Wyoming 82071, USA
Catherine E. Wagner
Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
Laurent Excoffier
Contributions
O.S., J.I.M. and C.E.W. designed the study; O.S. gathered and identified the cichlid samples; J.I.M., S.M. and D.A.M. performed the lab work (DNA extraction, mtDNA and LWS sequencing and RAD library preparation); J.I.M. conducted the analyses, with assistance from O.S., C.E.W., D.A.M. and L.E.; J.I.M. prepared the manuscript together with O.S. and C.E.W. and L.E. and D.A.M. contributed to writing.
Competing interests
The authors declare no competing financial interests.
Corresponding author
Correspondence to Ole Seehausen.
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NOTA DESTE BLOGGER:
Procure no artigo e não encontrá menção de mutação e/ou seleção natural como processos evolucionários. Darwin, isso é uma afronta!!! A hibridização é meramente o compartilhar de informação genética existente; ela não cria nada novo - os peixes ciclídeos continuaram peixes ciclídeos.
