* @param row The multiverse row.
* @param col The multiverse column.
*/
public synchronized void mutateSingle(final int row, final int col) {
final UniverseRunner target = this.grid[row][col].getUniverseRunner();
target.mutate(this.rnd, target.getPhysics(), 0.5, 0.2);
target.randomize(this.rnd);
}
/**
* Randomize a universe (both physics and state).