Eawag, the Swiss Federal Institute of Aquatic Science and Technology, is an internationally networked aquatic research institute within the ETH Domain (Swiss Federal Institutes of Technology). Eawag conducts research, education and expert consulting to achieve the dual goals of meeting direct human needs for water and maintaining the function and integrity of aquatic ecosystems.
PhD student in evolutionary ecology with specific focus on adaptive radiation of Arctic charr in post-glacial lakes
Adaptive radiation is a key driver in the origin of biodiversity in both deep and shallow evolutionary time. The process is characterized by environmental change leading to an adaptive zone, where a few colonizing species encounter multiple unoccupied ecological niches. When sufficient ecological divergent- or disruptive selection acts on such colonizers and is complemented by the evolution of assortative mating, new species can evolve in relatively short timespans. However, like the vast majority of all species to ever exist, most species evolved through adaptive radiation will eventually go extinct.
Past research has focused on the role of various components in facilitating speciation through adaptive radiation and potential subsequent extinctions. Nevertheless, no studies have been able to combine all components, i.e. ecological opportunity, assortative mating and time, with sufficient replication to make a quantitative assessment of the relative importance of different factors in the evolution and collapse of biodiversity. This requires an interdisciplinary approach, which considers both biological and geological data.
In this project, we will take advantage of a dynamic system, where ice marginal fluctuations of the Greenland Ice Sheet since the Last Glacial Maximum, including the modern anthropogenic warming, have created a large number of lakes with varying age and ecology. Lake ages vary between a few years and 15’000 years and the ecological opportunities range from ecologically depauperate silt-rich, cold lakes to ecologically more diverse clear-water lakes. All lakes were colonized during the Holocene by only two fish species, where one has shown multiple parallel cases of speciation within lake ecosystems in the region. Additionally, the regional relative sea level rise over the last thousands of years may have caused several larger freshwater lakes to turn into present-day marine incursions, a process potentially associated with the collapse of radiated fish taxa.
With the project, we aim to investigate different stages of the environmental- and evolutionary cycle from lake emergence, over lake environment succession, fish diversification- and speciation, and eco-evolutionary stabilization to eventual collapse. We take advantage of a deep insight in the geological and glaciological processes in the study area from the collaborating institute at University of Copenhagen and of the Eawag insight into the ecological and evolutionary structure and dynamics in the ecosystems and species of interest. Through the combination of analyses of sediment cores from multiple lakes and analyses of ecological and evolutionary distinctiveness of fish in the lakes, we will determine how lake succession affects colonization, ecological specialization, adaptive radiation and eventual biodiversity collapse in Arctic charr.
Applicants should have or anticipate finishing an MSc or similar before September 2023 in a relevant field of biology, ecology, or environmental science and a strong interest in evolutionary ecology, biodiversity and/or aquatic ecology. Excellent communication and writing skills in English and ability to work in a team are essential. The project is funded for four years by the Swiss National Science Foundation and the Independent Research Fund Denmark, through the program “International Co-Investigator Scheme” and is a collaboration with Prof. Nicolaj Krog Larsen at the GLOBE Institute at University of Copenhagen.
The main work place is at Eawag’s Center for Ecology, Evolution and Biogeochemistry (CEEB) in Kastanienbaum, Lucerne, which besides the Fish Ecology and Evolution Department hosts research group from the Department Surface Waters – Research & Management and offers a beautiful workplace at the shores of Lake Lucerne, a friendly international working climate and a strong cross-disciplinary research environment. Both departments within CEEB share a common interest in understanding the principles of the functioning of aquatic ecosystems and their susceptibility and adaptability to changing environments, and a common concern for sustainable management of ecosystems and biodiversity. Each department on its own aims at contributing cutting edge science to the development of theory in ecology, evolution and environmental sciences. Building on the synergies that emerge between these fields, the CEEB aspires to contribute to a future synthesis of evolutionary biology and ecosystem science.
is a modern employer and offers an excellent working environment where staff can contribute their strengths, experience and ways of thinking. We promote gender equality and are committed to staff diversity and inclusion. The compatibility of career and family is of central importance to us. For more information about Eawag and our work conditions please consult www.eawag.ch
must be submitted by 17 June 2023 and should include an application letter describing your interests and their relevance to this position, a CV, and the names and contact information for two references. The position should optimally start on 1 September 2023. For further information, please contact Dr Jakob Brodersen
/ +41 58 765 22 04).
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