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A cascade of evolutionary change alters consumer-resource dynamics and ecosystem function.
Matthew R Walsh1, John P DeLong, Torrance C Hanley
1Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA. matthew.walsh@yale.edu
Proceedings. Biological Sciences
|May 26, 2012
Summary
Intraspecific evolution in prey fish, Daphnia, alters population growth rates. This evolutionary change cascades through food webs, impacting ecosystem functions and demonstrating the ecological significance of evolutionary change.
Area of Science:
- Ecology
- Evolutionary Biology
- Ecosystem Science
Background:
- Intraspecific evolutionary divergence significantly impacts populations, communities, and ecosystems.
- Ecological effects of different phenotypes and genotypes can alter species selection and trigger cascading ecological and evolutionary changes across food webs.
- Theoretical frameworks predict evolutionary interactions across trophic levels contribute to ecology-evolution feedbacks, but empirical evidence from natural settings is limited.
Purpose of the Study:
- To investigate the reciprocal impacts of prey evolution on ecological processes.
- To experimentally evaluate the role of intraspecific life-history evolution in driving ecosystem function.
- To determine the importance of cascading evolutionary change in natural systems.
Main Methods:
- Laboratory mesocosm experiments were conducted to assess the ecological impacts of evolved Daphnia ambigua.
- Variation in alewife (Alosa pseudoharengus) predatory behavior and morphology was used to drive Daphnia life-history evolution.
- Population growth rates, consumer-resource dynamics, and ecosystem functions were measured.
Main Results:
- Life-history evolution in Daphnia ambigua led to divergent population growth rates.
- These evolutionary changes significantly altered consumer-resource dynamics.
- Evolved Daphnia populations demonstrated significant impacts on overall ecosystem function.
Conclusions:
- Experimental results demonstrate that Daphnia evolution significantly alters ecological processes and ecosystem function.
- These findings parallel trends observed in natural lake systems.
- Cascading evolutionary change occurring over contemporary timescales demonstrably alters community and ecosystem processes.
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