Department Fish Ecology and Evolution

Fish Ecology & Evolution (FishEc)

We study ecology, evolution and biodiversity of fishes and other aquatic organisms. We are interested in the mechanisms that drive the origins, the maintenance and the loss of species, genetic and functional diversity.


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June 21, 2021

A subterranean adaptive radiation of amphipods in Europe

Adaptive radiations are bursts of evolutionary species diversification that have contributed to much of the species diversity on Earth. An exception is modern Europe, where descendants of ancient adaptive radiations went extinct, and extant adaptive radiations are small, recent and narrowly confined. However, not all legacy of old radiations has been lost. Subterranean environments, which are dark and food-deprived, yet buffered from climate change, have preserved ancient lineages. Here we provide evidence of an entirely subterranean adaptive radiation of the amphipod genus Niphargus, counting hundreds of species. Our modelling of lineage diversification and evolution of morphological and ecological traits using a time-calibrated multilocus phylogeny suggests a major adaptive radiation, comprised of multiple subordinate adaptive radiations. Their spatio-temporal origin coincides with the uplift of carbonate massifs in South-Eastern Europe 15 million years ago. Emerging subterranean environments  likely  provided  unoccupied,  predator-free  space,  constituting  ecological opportunity, a key trigger of adaptive radiation. This discovery sheds new light on the bio-diversity of Europe. Original publication

May 06, 2021

Hybrid Animals Are Not Nature’s Mis

Science writer Ashley Yeager has written a nice piece in The Scientist about the paradigm shift in our understanding of the role that interspecific hybridization plays in the evolution of biological diversity, featuring on Oles Seehausen work and that of others ...

March 02, 2021

Invasiveness facilitated by a large gene pool

In Lake Constance, sticklebacks are occupying increasingly varied habitat types – in recent years even including the open and deep waters of the lake. In an Eawag review undertaken as part of the “SeeWandel” project, these uniquely diverse ecological adaptations are explained in terms of renewed contact between three stickleback lineages – including one originating from the Baltic region, whose genetic material is as yet rarely observed in other Swiss lakes. Read more  

open positions

Open positions at our division at University of Bern

Latest Publication

Marques, D. A.; Lucek, K.; Sousa, V. C.; Excoffier, L.; Seehausen, O. (2021) Reply to "Re-evaluating the evidence for facilitation of stickleback speciation by admixture in the Lake Constance basin", Nature Communications, 12, 2807 (5 pp.), doi:10.1038/s41467-021-23096-x, Institutional Repository

FishEc Seminare

9.00 am
Eawag Kastanienbaum
9.00 am
Eawag Kastanienbaum

Research Projects

We investigate the mechanisms of speciation and adaptive radiation
Genome evolution and genomic divergence across the Swiss Alpine whitefish radiation
Investigating the interactions between migration ecology, local adaptation and diversification