Figure 3.

Cryptic variation can facilitate evolutionary adaptation. (a) Each large rectangle represents a genotype space into which a hypothetical genotype network is inscribed (grey open circles connected by grey lines). The coloured circles symbolize individuals in a population on this genotype network. The population on the left (blue circles) is genotypically less diverse, and thus contains less cryptic variation than the population on the right (yellow circles). (b) A laboratory evolution experiment showing how fast two populations of ribozymes with indistinguishable phenotype (catalytic activity on an RNA substrate) but different amounts of cryptic genotypic variation adapt evolutionarily to a new RNA substrate. As in (a), blue and yellow correspond to populations with little and much cryptic variation. The horizontal axis shows time in generations and the vertical axis shows a measure of the biochemical activity of each population on the new RNA substrate. The population with more cryptic variation adapts faster [46].