Twenty-one allele frequencies of the human HLA loci from 58 localities in Europe and the Near East were subjected to spatial autocorrelation analysis. The frequencies were significantly heterogeneous over the localities. Significant clinal structure is shown by most allele frequencies. Collective study of the 21 variable surfaces and of their correlograms supports a hypothesis of migration leading to the observed patterns with three alternative explanatory hypotheses being eliminated. Cluster analysis of allele frequency surfaces and of correlograms shows that there are at least three distinct classes of patterns. By connecting localities along the established paths of the spread of agriculture into Europe, it can be shown that one of these surface clusters and their corresponding correlograms closely relate to the spread of farming. The results are compatible with a hypothesis of demic diffusion of early farmers into the hunter-gatherer population of Neolithic Europe first advanced by Ammerman and Cavall...