Abstract: Evolutionary algorithms are used to find a global solution to the fitting of experimental X-ray scattering data to simulated models. A recombination operator combines two or more parameter vectors from one iteration of simulated scattering data to form a new parameter vector for the next iteration, in a manner such that there is a high probability that the new parameter will better fit the experimental data than any of the parent parameters. A mutation operator perturbs the value of a parent vector, to permit new regions of the error function to be examined, and thereby avoid settling on local minima. The natural selection guarantees that the parameter vectors with the best fitness will be propagated into future iterations.