“Rapid Evolution” Method Found in Eyeless Fish

Hello,The Stickleback fish is another example of such retention of "switching" genes.Stickleback genomes reveal path of evolution | Nature

I think that the OP title "Rapid Evolution" is possibly
a misnomer insofar as what constitutes rapid in evolutionary time spans. The genetic templates are already in place and have probably been so for many thousands of years. It is the resultant environmental stressors or pressures that seemingly cause the morphological and physiological changes within the "few" generations. In other words the dominoes have been already put into place. At least from how I understand it. If one wishes to study rapid evolution they would be better off with bacteria or fruit flys.