Data from: Pumping ions: rapid parallel evolution of ionic regulation following habitat invasions

In contrast, freshwater populations displayed reduced Na+/K+-ATPase activity across all salinities. Most notably, modifying salinity alone during laboratory selection experiments recapitulated the evolutionary shifts in V-type H+ ATPase activity observed in nature. Maternal and embryonic acclimation could not account for the observed shifts in enzyme activity.

V-type H+ ATPase function has been hypothesized to be critical for freshwater and terrestrial adaptations, but evolution of this enzyme function had not been previously demonstrated in the context of habitat transitions. Moreover, the speed of these evolutionary shifts was remarkable, within a few generations in the laboratory and a few decades in the wild.