Survival of the sparsest: robust gene networks are parsimonious.
Biological gene networks appear to be dynamically robust to mutation, stochasticity, and changes in the environment and also appear to be sparsely connected. Studies with computational models, however, have suggested that denser gene networks evolve to be more dynamically robust than sparser networks. We resolve this discrepancy by showing that misassumptions about how to measure robustness in artificial networks have inadvertently discounted the costs of network complexity. We show that when the costs of complexity are taken into account, that robustness implies a parsimonious network structure that is sparsely connected and not unnecessarily complex; and that selection will favor sparse networks when network topology is free to evolve. Because a robust system of heredity is necessary for the adaptive evolution of complex phenotypes, the maintenance of frugal network complexity is likely a crucial design constraint that underlies biological organization.
Leclerc
Robert D
RD
Wagner Lab, Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA. robert.leclerc@yale.edu
D000222:Adaptation, Physiological / Q000235:genetics; D003198:Computer Simulation; D019143:Evolution, Molecular; D053263:Gene Regulatory Networks; D005838:Genotype; D040941:Heredity; D006801:Humans; D008297:Male; D008957:Models, Genetic; D009154:Mutation; D015203:Reproducibility of Results; D012641:Selection, Genetic; D013269:Stochastic Processes; D014158:Transcription, Genetic