The New York Times has an interesting article in which scientists have used GAs to discover a form of Boron nearly as hard as diamond:
For that, they turned to Dr. Oganov, who employed a computational technique that encodes parameters of the crystal structure in a string of data. Starting with a number of trial crystal structures, the program calculates the energy needed to hold each together, and discards the versions that do not pack together comfortably. Then, as occurs in biological evolution, the crystal parameters are tweaked (the equivalent of mutation) and portions of the structure swapped (the equivalent of recombination). After generations of calculation, the answer converges on the stable form.
See the full article here.