Project groups

8-2.1 | EVOLUTIONARY ADAPTATION POTENTIAL AS A FUNCTION OF TIME

Project leader:
Prof. Dr. Bruno Streit

The adaptation potential of aquatic species varies as a function of time. It can be reduced by selection, or increased by a high level of phenotypic plasticity or gene flow. Changes can only be observed by monitoring animals over several generations. This would require studies spanning several years or decades, which explains why this assumption has not been tested on natural populations so far.

We have optimised a technique to reanimate zooplankton species, especially of the genus Daphnia, from resting eggs that settled in sediments several decades ago. This technique allows studies on changes in adaptation potential going back at least as far the middle of the 20th century.

Methodology: Resting eggs are separated from the sediment and hatching is induced. In common-garden experiments the juveniles are exposed to different temperature conditions. The ecological differentiation in fitness-relevant traits, such as reproduction rate, is compared with the differentiation at different neutral loci. This approach enables us to check the assumption for changes in adaptation potential (in relation to natural selection) and to demonstrate the dimension.

Using a key species (D. galeata), we investigate the chronological (C5.1) and spatial (C5.2) aspects of adaptation potential. This project is complementary to project C5.2  and is closely connected to the projects C2.1 and D5.1.


Team

Nicole Henning, Ph.D. student
Elke Völker, Technician

Publications

Dlouhá, S., Thielsch, A., Kraus, R.H.S., Seda, J., Schwenk, K. & A. Petrusek (2010) : Identifying hybridizing taxa within the Daphnia longispina species complex: a comparison of genetic methods and phenotypic approaches. - Hydrobiologia 643 (1), 107-122.

Jansen, M., Schulze, A., Werding, L. & B. Streit (2009) : Effects of extreme drought in the dry season on an anuran community in the Bolivian Chiquitano region. - Salamandra 45: 233-238.

Krutschinna, J. & B. Streit (2009) : The biodiversity network BioFrankfurt: An innovative strategic approach for integrative research, conservation, and education. - BioRisk 3: 21-26.

Plath, M., Hermann, B., Schröder, C., Riesch, R., Tobler, M., García de León, F.J., Schlupp, I. & R. Tiedemann (2010) : Locally adapted fish populations maintain small-scale genetic differentiation despite perturbuation by a catastrophic flood event. - BMC Evolutionary Biology 10: 256.

Seidendorf, B., Meier, N., Petrusek, A., Boersma, M., Streit, B. & K. Schwenk (2010) : Sensitivity of Daphnia species to phosphorus-deficient diets. - Oecologia 162:349–357.

Streit, B., Böhning-Gaese, K. & V. Mosbrugger :

Biodiversität und Klima: Wandel in vollem Gange! Eine globale Herausforderung und ein Forschungszentrum. - Biologie in unserer Zeit, Volume 41, Issue 4, pages 248-255; DOI: 10.1002/biuz.201110455


Link to Publication

Streit, B. (2010) : Verlust der biologischen Vielfalt. Über spekulative Zahlen und realisierbare Ziele. - Forschung & Lehre 9/10, S. 654-656
Download publication, PDF 578 KB

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