A general strategy is introduced for analysing the evolutionary events that occur during a genetic algorithm calculation, and the application of this approach is illustrated for the specific case of understanding the evolutionary trajectory leading to the correct structure solution in structure determination from powder diffraction data. Methods providing visual representations of the evolution of the population during a genetic algorithm calculation are also introduced. It is demonstrated that our strategy can provide much more detailed insights concerning the evolutionary behaviour than was previously accessible, and can thus be exploited to further develop our genetic algorithm methodology. (C) 2002 Elsevier Science B.V. All rights reserved.