Abstract: A method of and apparatus are disclosed for evolving successive populations of molecular structures and evaluating each evolved structure of each population with desired physical and/or theoretical properties. An initial population of molecules is provided in terms of representations of a number of member molecules. Evaluation is performed by a fitness function, which compares the initial population and evolved generations of member representations with the set of desired properties to provide a numerical measure or value of fitness for each structure. That numerical value indicates how closely the compared member representation corresponds with the set of desired properties. The next population is generated by changing the structure of selected molecules of a population dependent upon the numerical measure of fitness, and the process repeats. Subsequent populations evolve towards ever-better fitness. The process is terminated when an acceptable molecule evolves.