Resurrected Daphnia as a model organism to investigate micro-evolutionary adaptations of natural populations to multiple stressors in the environment

Project duration: 2019–2022


Funding: Start-Up Postdoctoral funds; GU GRADE FOCUS Junior Researcher funds


Principle investigator
  • Dr. Sarah Crawford

Affiliated researchers
  • Prof. Dr. Henner Hollert

Project description

This research examines the effects of environmental contaminants in combination with changes in temperature in natural populations of lake systems. Long-term exposure to environmental stressors can lead to genetic adaptations in exposed populations of aquatic organisms, such as Daphnia (Crustacea: Cladocera), which are a keystone species in lake systems (food webs). Eggs produced by Daphnia sp., can become dormant as a result of unfavourable environmental conditions, and can settle and be archived in sediments. Dormant eggs can be dated and hatched to produce clonal lineages (i.e., same genotypes) of historical populations (i.e., resurrection ecology). The emerging research fields of evolutionary toxicology and resurrection ecology offer powerful tools that have not previously been used to investigate changes in sensitivities and adaptive trajectories of populations exposed to multiple environmental stressors. We will examine how genotypes of clonal lineages of Daphnia sp. from single populations, separated through generations of evolution, differ in their response to exposure of environmental stressors. Since increased temperatures are expected to occur according to climate change scenarios, exposure of historical and recent clones of Daphnia to both contaminants and increasing temperatures will provide insight into the sensitivity and fitness of a keystone sp. (figure). Additional insight will be gained regarding the micro-evolutionary adaptations of genes in response to multiple stressors, to better understand future evolutionary changes of Daphnia in response to changing environments. Toxicological assessments and genomic data obtained from exposure of Daphnia populations will provide unprecedented opportunities to gain insight into long-term and potentially future evolutionary responses of a keystone sp. in the face of changing environments, providing feedback for risk assessment and future management of lake systems (i.e., collapse of grazers/impacts on upper trophic levels).

Contact

Prof. Dr. Dr. h.c. Henner Hollert

Goethe University Frankfurt
Biologicum, Campus Riedberg
Max-von-Laue-Str. 13
60438 Frankfurt am Main, Germany

Room: 3.319
Phone: +49 (0)69 798 42171
Fax: +49 (0)69 798 42161
Email: hollert(at)bio(dot)uni-frankfurt(dot)de

Former Affiliation:
http://www.bio5.rwth-aachen.de