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04:52
Following the Dynamics of Structural Variants in Experimentally Evolved Populations
Published on: February 3, 2023
Epistasis can lead to fragmented neutral spaces and contingency in evolution
Steffen Schaper1, Iain G Johnston, Ard A Louis
1Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford, UK.
Proceedings. Biological Sciences
|December 14, 2011
Summary
Epistasis allows second mutations to compensate for deleterious effects, but this can fragment genome space. Neutral networks for RNA folding often break into components, impacting evolvability and robustness.
Area of Science:
- Evolutionary biology
- Genomics
- Molecular biology
Background:
- Deleterious mutations can be compensated by compensatory mutations through epistasis.
- Epistatic interactions influence the connectivity of genome space, where genotypes map to phenotypes.
- Understanding these connections is crucial for evolutionary dynamics.
Purpose of the Study:
- To explore neutral spaces and genotype-phenotype maps using RNA folding.
- To investigate the connectivity of networks of genotypes encoding the same phenotype.
- To analyze the impact of network fragmentation on evolutionary properties.
Main Methods:
- Utilizing RNA sequence folding into secondary structures as a model genotype-phenotype map.
- Analyzing neutral spaces representing networks of genotypes with identical phenotypes.
- Quantifying the fragmentation of these networks into neutral components.
Main Results:
- Most neutral networks fragment into at least 2(n) components for a phenotype with n bonds.
- These components, while sharing a phenotype, exhibit significant variations.
- Key variations were observed in evolvability and mutational robustness among components.
Conclusions:
- Genome space is not always continuously connected by single mutations due to epistasis.
- Network fragmentation leads to heterogeneity in evolutionary properties within a phenotype.
- This heterogeneity introduces contingency into the evolutionary process.
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