An evolutionary algorithm is a type of non-deterministic search. The algorithm is searching the space of all possible solutions to find one that is good enough. The larger the search space, the longer it is likely to take to converge on a satisfactory solution. For this reason, anything we can do to constrain the search space, without handicapping the algorithm, is likely to be beneficial. This includes choosing an efficient candidate representation and using evolutionary operators that avoid generating useless or invalid solutions. A little intelligent design can go a long way.