Friend or Foe

A new DFG-Research Group in cooperation with the University of Konstanz

How different species interact with each other, such as predator and prey, is by no means fixed and can depend on the prevailing environmental conditions. The new DFG research group "DynaSym" is investigating which factors play a role in this process.
 

How rigid are the relationships between different species? For example, does a predator always behave as a predator towards its prey? And do species that compete for the same nutrients remain competitors forever? For a long time, ecology and evolutionary research assumed that such relationships between different species were indeed fixed. However, it is now known that they can change—depending on environmental conditions.

One of the key questions of the new research group "Density dependent symbiosis in planktonic systems" (DynaSym), whose funding was announced today, July 2, 2024, by the German Research Foundation (DFG), is the role played by population densities of the interacting species—that is, the number of individuals of each species within a given habitat. The DFG will initially fund the collaboration for four years, starting in October 2024. The speaker of DynaSym is ecologist and evolutionary biologist Lutz Becks from the Department of Biology at the University of Konstanz.

Combining theoretical and experimental approaches

"Using microorganisms as model organisms, we want to determine what density-dependent changes occur in the interaction between species and what their consequences are for population and community dynamics," explains Becks. Under what conditions, for example, does a competitive relationship turn into symbiosis, a relationship that benefits both species involved? And do such changes feedback on population densities—are there feedback mechanisms?

The research group will tackle eight sub-projects, distributed across six German universities and research institutes. Additionally, there will be collaboration with partners from France, Israel, and the USA. The combination of experimental and theoretical, modeling approaches in these projects aims to provide new, general mechanistic insights into the dynamics of organismal communities, revising and expanding existing theories in ecology. "With our interdisciplinary approach, bringing together experts in experimental ecology and evolution with modelers, we are ideally positioned to comprehensively explore the processes underlying the complex dynamics of ecological communities," Becks says.

Sub-project in Plön: Symbionts, Immunity, and Parasite Epidemics

As part of the DFG funding, Dr. Hildegard Uecker from the Max Planck Institute for Evolutionary Biology in Plön will receive support for her sub-project, "Density dependence of symbiont-mediated immunity and parasite epidemics in symbiont-protected host populations." The project focuses on symbionts that provide their host with protection against parasites but also incur costs in the absence of these parasites, essentially becoming parasites themselves, albeit less harmful. The focus is on studying the context-dependent nature of this symbiosis and its effects on parasite epidemics. The study will analyze how the densities of all three partners change during the course of a parasite epidemic and how these density changes interact with the form of the symbiosis. Classical host-parasite theory is insufficient to describe the dynamics of such systems with a third interacting partner. In collaboration with other members of the research group, models specifically for planktonic systems will be developed in addition to fundamental theory. Dr. Uecker will hire a PhD student for the project.

About DFG Research Groups

In total, the German Research Foundation is establishing nine new research groups and one new college research group, as announced today, July 2, 2024. The goal of the DFG research groups is to foster medium-term collaboration among several outstanding scientists on a specific research task, enabling the consortium to achieve results that go far beyond what individual funding would allow. The maximum funding duration of a research group is twice four years. In the first funding period, the nine new research groups will receive a total of around 41.3 million euros.

 

Fact Overview:

• The German Research Foundation (DFG) is establishing nine new research groups and one new college research group.
• The research group "Density dependent symbiosis in planktonic systems" (DynaSym) investigates the influence of population densities on the interactions between different species.
• The spokesperson for DynaSym is Prof. Lutz Becks, an ecologist and evolutionary biologist from the Department of Biology at the University of Konstanz.
• Project leaders and research institutions involved in DynaSym:
  • Prof. Lutz Becks (University of Konstanz)
  • Prof. Ursula Gaedke, Dr. Toni Klauschies, and apl. Prof. Guntram Weithoff (University of Potsdam)
  • Dr. Birte Matthiessen (GEOMAR Helmholtz-Center for Ocean Research, Kiel)
  • Dr. Stefanie Moorthi (University of Oldenburg)
  • Prof. Herwig Stibor and Dr. Maria Stockenreiter (Ludwig Maximilian University of Munich)
  • Dr. Hildegard Uecker (Max Planck Institute for Evolutionary Biology, Plön)
• International collaborators:
  • Prof. Frida Ben-Ami (Tel Aviv University, Israel)
  • Prof. Meghan Duffy (University of Michigan, USA)
  • Prof. Jelena Pantel (University of Franche-Comté, France)