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Understanding the limits to generalizability of experimental evolutionary models
Samantha E Forde1, Robert E Beardmore, Ivana Gudelj
1Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, California 95064, USA.
Nature
|September 12, 2008
Summary
In vitro models and mathematical modeling reveal how resource input affects co-evolutionary diversity. Different host-parasite interactions show distinct diversity patterns, supporting the geographic mosaic theory.
Area of Science:
- Evolutionary biology
- Ecological theory
- Microbial systems
Background:
- Testing evolutionary and ecological theories in situ is challenging.
- In vitro model systems offer an alternative for experimental research.
- Assessing the generalizability of in vitro findings is crucial.
Purpose of the Study:
- To determine if experimental results are specific to in vitro models.
- To characterize systems that may behave differently and explain why.
- To investigate the relationship between phenotypic diversity and resource input in co-evolving systems.
Main Methods:
- Developed a mathematical model for the T7-Escherichia coli co-evolving system.
- Validated the model against experimental results.
- Tuned the model to simulate alternative co-evolving partners and interactions.
Main Results:
- Co-evolving populations consistently show variation in diversity with resource input, unlike non-co-evolving populations.
- The specific pattern of diversity variation depends on the details of infectivity and interaction type.
- Gene-for-gene interactions in T7-E. coli result in low diversity at high resource input.
- Matching-allele interactions lead to maximal diversity at high resource input.
Conclusions:
- A combination of in vitro systems and mathematical models effectively isolates system-specific results.
- This approach can characterize alternative biological systems and explain underlying mechanisms.
- Findings support the geographic mosaic theory of co-evolution, highlighting the context-dependency of evolutionary outcomes.
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