The Scientist - Hybrid animals are not nature's misfits

Die Wissenschaftsjournalistin Ashley Yeager hat in der Zeitschrift “The Scientist” einen schönen Artikel über den Paradigmenwechsel in unserem Verständnis über die Rolle, die zwischenartliche Hybridisation in der Evolution von Biodiversität spielt, geschrieben. Darin beschreibt sie unter anderem auch unsere Arbeit im Zusammenhang mit Hybridisation in Viktoriasee-Buntbarschen.

Nature Communications - Admixture between old lineages facilitates contemporary speciation in Lake Constance sticklebacks

Anpassung an eine neues Habitat kann dazu führen, dass in kurzer Zeit ein neue Arten entstehen. Wie das genetisch möglich ist, ist aber bisher kaum bekannt. Eine neue Publikation in Nature Communications von David Marques, Kay Lucek, Vitor Sousa, Laurent Excoffier und Ole Seehausen zeigt nun auf, dass die Dreistachligen Stichlinge im Bodensee aus der Hybridisierung zwischen zwei Stichlingsarten aus West- und Osteuropa hervorgegangen sind. Der Austausch von genetischem Material hat innerhalb der osteuropäischen Stichlingsart zur raschen Evolution von Fluss- und Seeökotypen beigetragen, welche nun selbst wie zwei Arten Seite an Seite brüten. Bodensee-Stichlinge, wie auch Viktoriasee-Buntbarsche, zeigen deshalb auf, dass Hybridisierung ein wichtiger genetischer Faktor sein kann für die Entstehung neuer Arten innert kürzester Zeit.
Der Link führt zu einem Blog über die Publikation.

SCIENCE - A key metabolic gene for recurrent freshwater colonization and radiation in fishes

Since the last ice age, stickleback have managed to emerge from the sea to colonise many freshwater waterbodies. Genetic analysis by researchers in the Division of Aquatic Ecology & Evolution and the Division of Evolutionary Ecology at the University of Bern, and colleagues from the Eawag and the National Institute of Genetics in Shizuoka, Japan, now demonstrate that they achieved this thanks to additional copies of a metabolism gene.

Dem Luchs droht im Wallis die Ausrottung

Die Universität Bern warnt vor dem extrem tiefen Luchsbestand im Kanton Wallis. Geht es so weiter, könnte der Luchs in der Region bald Geschichte sein.

Evolutionary conserved neural signature of early life stress affects animal social competence

The social environment experienced by young animals can persistently influence their social competence later in life. However, it is largely unknown, which molecular mechanisms drive ontogenetic variation in animal social competence. In a recent article in the Proceedings of the Royal Society B, Cecilia Nyman, Stefan Fischer, Nadia Aubin-Horth and Barbara Taborsky showed that the vertebrate stress axis (the 'HPI axis' of fish) plays a key role for the development of social competence. In the cooperatively breeding cichlid Neolamprologus pulcher, they showed that (1) the molecular pathway translating early social experience into later-life alterations of the stress axis and into changes of social competence is homologous across vertebrates, and (2) that pharmacological manipulation of the stress axis leads to improved social competence.

Genetic coupling of female traits and female preference facilitates speciation

How are associations between traits under divergent selection and traits that contribute to assortative mating maintained in the face of gene flow during ecological speciation? In a new paper in Current Biology, Catherine Peichel, Dolph Schluter (University of British Columbia) and colleagues answer this question using a classic model of ecological speciation, sympatric benthic-limnetic sticklebacks. To allow for recombination between loci underlying assortative mating and those under divergent ecological selection, they assessed the mate choice of benthic-limnetic stickleback F2 hybrid females for wild benthic or limnetic males under natural conditions in ponds. Remarkably, F2 females chose males with a similar body shape and size to their own. Furthermore, genetic loci associated with F2 female mate choice also predicted F2 female morphology. These data provide empirical evidence to support the long-standing theoretical prediction that genetic coupling between assortative mating and traits under divergent selection can facilitate speciation in the face of gene flow.

Dem Admiral auf der Spur

Das prächtige Herbstwetter der letzten Tage bot ideale Bedingungen, um ein ganz besonderes Phänomen zu beobachten. Die Rede ist von der Wanderung des Admirals. Dieser auffällige Tagfalter zieht momentan zu Tausenden durch die Schweiz. Im Rahmen seiner Dissertation untersucht Marco Thoma vom Institut für Ökologie und Evolution die Admiralwanderung und berichtet darüber für «uniaktuell».

NatureEcolEvol - Transgenerational selection driven by divergent ecological impacts of hybridizing lineages

Rebecca und Kollegen haben eine aufregende neue Studie über Generationen übergreifende eco-evolutionary feedbacks publiziert. In diesem Experiment haben sie Dreistachlige Stichlinge von zwei unterschiedlichen evolutionären Linien (eine vom Genfersee und die andere vom Bodensee) und deren Hybride benutzt. Sie haben gefunden, dass (i) es den Junfischen der nächsten Generation weniger gut geht, in den Mesokosmen, die von Adulten der eigenen Linie verändert wurden, als in solchen, die von den anderen Linien verändert wurden (besonders offensichtlich bei der Genfersee-Linie) und (ii) dass die F1 Hybriden besser überleben und fitter sind, als die nicht-hybriden Jungtiere von beiden Linien un dder Vorteil der Hybride war besonders augenfällig, wenn die Ressourcen limitierend waren. Lesen Sie mehr auf Rebeccas tollem "Behind the paper" blog auf https://tinyurl.com/y7u6ebcv .

NatureEcolEvol - Transgenerational selection driven by divergent ecological impacts of hybridizing lineages

Rebecca und Kollegen haben eine aufregende neue Studie über Generationen übergreifende eco-evolutionary feedbacks publiziert. In diesem Experiment haben sie Dreistachlige Stichlinge von zwei unterschiedlichen evolutionären Linien (eine vom Genfersee und die andere vom Bodensee) und deren Hybride benutzt. Sie haben gefunden, dass (i) es den Junfischen der nächsten Generation weniger gut geht, in den Mesokosmen, die von Adulten der eigenen Linie verändert wurden, als in solchen, die von den anderen Linien verändert wurden (besonders offensichtlich bei der Genfersee-Linie) und (ii) dass die F1 Hybriden besser überleben und fitter sind, als die nicht-hybriden Jungtiere von beiden Linien un dder Vorteil der Hybride war besonders augenfällig, wenn die Ressourcen limitierend waren. Lesen Sie mehr auf Rebeccas tollem "Behind the paper" blog auf https://tinyurl.com/y7u6ebcv .

Geography uncovers ancient origins of RNA viruses

A new study conducted by Moritz Saxenhofer and Gerald Heckel shows that the time scales of virus evolutionary histories might be severely underestimated by state-of-the-art methods commonly used to date pathogen emergence. They included information about the geographic origin of virus samples to improve the age estimates for two European hantaviruses indicating that these are at least ten to a hundred times older than previously inferred based on sequence data alone. The results published with colleagues in the Proceedings of the Royal Society B provide valuable insights to better understand pathogen evolution and disease emergence.

Evolutionary Ecology

Research on the contribution of changes in chromosome structure and number to evolutionary processes has recently undergone a renaissance. This has been catalyzed by detailed knowledge of the molecular mechanisms that underlie chromosome structure and function, as well as advances in genome sequencing. To bring together molecular and evolutionary biologists working on chromosome evolution, Katie Peichel organized a Presidential Symposium of the American Genetic Association on the topic: “Chromosome Evolution: Molecular Mechanisms and Evolutionary Consequences”. This conference also resulted in a special issue edited by Katie for the Journal of Heredity, which has just been published.

IEE Students awarded at biology17

Students from the IEE won several awards at biology17 in Bern! Malie Lessard-Therrian (Conservation Biology), Carmela Dönz (Aquatic Ecology), and Manon Schweinfurth (Behavioural Ecology) all won Best Talk awards in their respective fields. Sophie Archambeault (Evolutionary Ecology) won a Best Poster award.

Best Poster awards at biology17

Students from the IEE won Best Poster awards at biology17 in Bern! Sophie Archambeault (Evolutionary Ecology) and Stefanie Roder (Conservation Biology) won a Best Poster award.

Aquatic Ecology - TREE - The Ecology and Evolution of Stoichiometric Phenotypes

Eawag Fellow Miguel Leal, Ole and Blake published an opinion paper in TREE about the ecology and evolution of stoichiometric phenotypes. The stoichiometric or elemental phenotype is defined by the elemental composition, assimilation, allocation, or excretion of an individual, measured as its elemental content or ratios between elements. Miguel et al discuss how variation in the elemental phenotype among individuals can affect individual fitness variation and how the evolution of elemental phenotype can influence ecosystem processes. They make suggestions for a research program to address these questions. This research might improve our ability to predict how organisms adapt to changing environmental conditions and may contribute to our understanding of eco-evolutionary feedbacks.

Community Ecology

The Theodor-Kocher-Award for 2016 has been awarded to Eva Knop (Community Ecology) and Sonja Kleinlogel (Medical Faculty). Eva Knop had been honored for her outstanding research in the field of urban ecology, biodiversity and ecosystem services.

Volz Award Winners 2016

The Volz Award for 2016 has been awarded to Laura Bruppacher (best publication from MSc thesis: Simple modifications of mowing regime promote butterflies in extensively managed meadows: Evidence from field-scale experiments) and David Marques (best publication from PhD thesis: Genomics of Rapid Incipient Speciation in Sympatric Threespine Stickleback). They both presented their work as part of the seminar Lecture Series in Ecology and Evolution on December, 13th, 2016. The board of directors congratulates them for their success and whishes them all the best for their upcoming scientific career.

Exceptionally low lynx density in Valais

A study conducted by the University of Bern in the past five winters has revealed an exceptionally low density of lynx in the canton of Valais. This result contrasts with density measured in other mountainous areas of Switzerland, as well as with the situation in Valais in the 1980s. Ongoing investigations tests different hypotheses for this low population density. Poaching might well be the most plausible cause according to the scientists.

Science - Chimpanzee genomic diversity reveals ancient admixture with bonobos

Modern non-African human genomes contain genomic remnants that suggest that there was interbreeding between ancient humans and archaic hominoid lineages. Now, an international consortium of researchers, including Prof. Laurent Excoffier and his team, show similar ancestral interbreeding between the ancestors of today's chimpanzees and bonobos. The study also provides population-specific genetic markers that may be valuable for conservation efforts.

Nature - A genomic history of Aboriginal Australia

It remains debated how Australia was initially populated and how changes in language and culture in the continent happened. Australia contains some of the oldest archaeological evidence of modern humans outside Africa dating back to about 50,000 years. Still about 90% of Aboriginal Australians speak languages belonging to a single linguistic family that dates back no more than a few thousand years. The first population genomic study on Aboriginal Australians published today in Nature provide some of the answers. This study has been conducted by a group of international researchers, including nine Aboriginal leaders. It has been led by Prof. Eske Willerslev from the Copenhagen-based Centre for GeoGenetics, Cambridge University and the Sanger Institute. Assistant Prof. Anna-Sapfo Malaspinas, Prof. Laurent Excoffier and his team from the University of Bern and the SIB Swiss Institute of Bioinformatics are part of the study.

Predators drive social complexity

Variation in social organization and behaviour of highly social animals is typically explained by habitat saturation and limited breeding opportunities. A recent study of Lake Tanganyika cichlids published in PNAS reveals that predation risk and related ecological factors strongly affect social complexity, thereby stressing the significance of predation for social evolution.

Community Ecology

The disconnect between science and practice is a long-recognised concern in restoration ecology, however, there is a distinct lack of practical solutions. In a new paper in Trends in Plant Science, Myles Menz and colleagues from the University of Western Australia present a practical framework to address this issue. The framework builds upon a successful model developed for American agriculture, stressing the critical issue of science-practice communication and integration as key to achieving global restoration targets.

Aquatic Ecology

New paper in PLoS Genetics on genomics of a very early stage of speciation by David Marques and colleagues. In only 150 years, threespine stickleback have evolved lake and stream ecotypes in Lake Constance, Central Europe. We found differentiation on multiple chromosomes persisting even in sympatry, suggesting early ecological speciation.

Behavioural Ecology

In contrast to prevailing opinion, kin selection is often not involved in the evolution of cooperation. A special issue of the Philosophical Transactions of the Royal Society compiled and edited by Michael Taborsky, Joachim Frommen and Christina Riehl shows both at theoretical and empirical levels that the degree of cooperation can advance even further if selected by alternative evolutionary mechanisms than by kin selection.

Population Genetics

The further a population moves away from its place of origin, the more harmful mutations it will carry. This is the result of a study conducted by Prof. Laurent Excoffier and his team, as part of an international collaboration led by Brenna Henn from Stony Brook University and Carlos Bustamante from Stanford University.
The researchers analysed genomes of individuals across four continents while former studies had only been carried out on two populations. The study has now been published in the Proceedings of the National Academy of Sciences.

Bernese Prize for Environmental Research 2015/16