Elizabeth Pennisi comments on three comparative studies of the genetics of modern fish and terrestrial tetrapods in the latest online issue of Science News. Apparently some fish genes were, perhaps fortuitously, ‘multipurpose’. They may have been exploited during the Devonian colonisation of land to help evolution of limbs, lungs and aspects of the nervous system to adapt shallow-water fishes to climb out onto dry land. (Pennisi, E. 2021. Fish had the genes to adapt to life on land—while they were still swimming the seas. Science, News 10 February 2021; DOI: 10.1126/science.abg9265).