Mutation and Crossover
Mutation: Makes a move or a perhaps a sequence of moves in the state space. If the direction of moving is random, there is a good chance to escape from local maxima.
Type 1: A random modification of one atomic unit -- one gene.
Type 2: A reordering of genes, .e.g, a transposition of two genes.
Crossover: Formation of a genetic blueprint for a new individual by splicing together a piece from individual A with a piece from individual B.
If A and B are each very fit, but in different ways, perhaps crossover will produce an even more fit individual.