Sanakirja.org

The quality of being robust.

A network of genotypes linked by mutations. Each genotype is made up of 3 genes: a, b & c. Each gene can be one of two alleles. Lines link different phenotypes by mutation. The phenotype is indicated by colour. Genotypes abc, Abc, aBc and abC lie on a neutral network since all have the same, dark phenotype. Genotype abc is robust since any single mutation retains the same phenotype. Other genotypes are less robust as mutations change the phenotype (e.g. ABc).

The quality of being robust.

Core eukaryotic metabolic network. Circles indicate metabolites and lines indicate conversions by enzymes. Many metabolites can be produced via more than one route, therefore the organism is robust to the loss of some metabolic enzymes

The quality of being robust.

Each circle represents a functional gene variant and lines represent point mutations between them. Light grid-regions have low fitness, dark regions have high fitness. (a) White circles have few neutral neighbours, black circles have many. Light grid-regions contain no circles because those sequences have low fitness. (b) Within a neutral network, the population is predicted to evolve towards the centre and away from 'fitness cliffs' (dark arrows).