Fishes are the most diverse group of vertebrates, are key players in aquatic ecosystems, provide a diverse set of ecosystem services, and are sensitive to environmental change. We study their ecology, evolution and conservation. We work with fish diversity from traits and genes in populations to the diversity of species assemblages, their change through time and the ecosystem consequences. We are particularly interested in understanding the evolution of endemic diversity within individual ecosystems, such as the radiations of cichlid fish in African lakes and the radiation of whitefish in the lakes around the European Alps. We are a single research group led by Ole Seehausen at the University of Bern but Ole also leads the Department Fish Ecology and Evolution at the Eawag Center for Ecology, Evolution and Biogeochemistry, Kastanienbaum, where we currently host three other research groups that are all associated with the IEE too. The work of the Eawag department is motivated by the aim to contribute to the emerging synthesis between evolutionary biology and ecosystems ecology. There we also host the Swiss Fisheries Advisory Service.
Nature Communications - Ancient hybridizations fuels rapid cichlid fish adaptive radiations
Joana Meier, Laurent Excoffier, Ole Seehausen and colleagues published a paper in Nature Communications. They shed light on how 700 diverse cichlid species could evolve in only 150,000 years in the Lake Victoria Region. By combining extensive taxon sampling and genomic analyses, they demonstrate that the entire “superflock” evolved from a hybrid swarm of two divergent cichlid lineages. The hybridization event facilitated the adaptive radiations by providing genetic variation that subsequently became recombined and sorted into many new species.