Criticality Is an Emergent Property of Genetic Networks that Exhibit Evolvability

摘要: Accumulating experimental evidence suggests that the gene regulatory networks of living organisms operate in critical phase, namely, at transition between ordered and chaotic dynamics. Such dynamics network permits coexistence robustness flexibility which are necessary to ensure homeostatic stability (of a given phenotype) while allowing for switching multiple phenotypes (network states) as occurs development response environmental change. However, mechanisms through genetic evolve such behavior have remained elusive. Here we present an evolutionary model criticality naturally emerges from need balance two essential components evolvability: phenotype conservation innovation under mutations. We simulated Darwinian evolution random Boolean mutate interactions grow by duplication. The mutating were subjected selection both (i) preserve all already acquired (dynamical attractor (ii) generate new ones. Our results show this interplay extending phenotypic landscape (innovation) conserving existing (conservation) suffices cause population towards criticality. Furthermore, produced process exhibit structures with hubs (global regulators) similar observed topology real networks. Thus, dynamical certain elementary topological properties can emerge byproduct evolvability landscape.