Evolvability articles from across Nature Portfolio

Testing the consequences of mitochondrial endosymbiosis in a theoretical approach, genome expansion and asymmetry in genome size stem from host–symbiont cell-cycle coordination.

Genotype networks are sets of genotypes connected by small mutational changes that share the same phenotype. Here the authors combine construction of over 20 synthetic gene regulatory networks with mathematical modeling to exemplify how gene regulatory networks provide robustness in face of mutations while enabling transitions to innovative phenotypes.

Directed evolution shows that low expression of the green fluorescent protein facilitates the evolution of cyan fluorescence in E. coli, which can be explained by synergy between the protein’s scarcity and its stability.

Brennan Klein et al. propose an adapted network resilience measure, the prospective resilience (PR), to explore the resilience of protein–protein interaction networks following addition of new nodes. They apply PR to public datasets and find that resilience of a network is maximized when attachment of new nodes, or proteins, is based on the gene expression levels of the existing proteins in the network.

Fitness landscapes were described almost a century ago as smooth surfaces with peaks and valleys that are difficult to navigate. Now, more realistic high-dimensional genotype–phenotype maps show that fitness maxima can be reached from almost any other phenotype while avoiding fitness valleys, which are very rare.