Evolutionary robotics is an interesting novel approach to shape the control system of autonomous robots. This explores issues related to re-adaptation in changed environments of a population of evolved individuals. Experimental studies are reported for genetic evolution of neurocontrollers that have developed the ability to perform homing navigation for battery recharge of miniature mobile robot. It is shown that re-adaptation to important changes in the environment is very rapid and does not disrupt previously acquired knowledge. The results are discussed in relation to the internal representation of the neurocontroller and to the variability within the population.