Gene duplication and subsequent diversification strongly affect phenotypic evolvability and robustness

• Main Authors: V. Jouffrey, A. S. Leonard, S. E. Ahnert
• Format: Article
• Language: English
• Published: The Royal Society 2021-06-01
• Series: Royal Society Open Science
• Subjects: genotype–phenotype map; gene duplication; self-assembly; Polyomino
• Online Access: https://royalsocietypublishing.org/doi/10.1098/rsos.201636

We study the effects of non-determinism and gene duplication on the structure of genotype–phenotype (GP) maps by introducing a non-deterministic version of the Polyomino self-assembly model. This model has previously been used in a variety of contexts to model the assembly and evolution of protein quaternary structure. Firstly, we show the limit of the current deterministic paradigm which leads to built-in anti-correlation between evolvability and robustness at the genotypic level. We develop a set of metrics to measure structural properties of GP maps in a non-deterministic setting and use them to evaluate the effects of gene duplication and subsequent diversification. Our generalized versions of evolvability and robustness exhibit positive correlation for a subset of genotypes. This positive correlation is only possible because non-deterministic phenotypes can contribute to both robustness and evolvability. Secondly, we show that duplication increases robustness and reduces evolvability initially, but that the subsequent diversification that duplication enables has a stronger, inverse effect, greatly increasing evolvability and reducing robustness relative to their original values.