[Computer technology of genogeographic study of the gene pool. IV. Population in the space of principal components].

On the basis of maps of principal components ("synthetic maps"), populations were arranged in the space of principal components. In terms of the applied model, nodes of a dense, uniform grid represented human populations. For each node, the frequency of a given gene was interpolated from these values for all original populations. Principal components were estimated and mapped on the basis of maps for all genes. Each population (grid node) was assigned a marker of an ethnic or some other group of populations and was positioned in the space of principal components according to the values from the original maps. The resultant "ethnic clouds" of populations and "ethnic centroids" of principal components provide some new possibilities for explaining the patterns of changes in gene pools. The maps of reliability of principal components allow the researcher to eliminate the information on populations which is unreliable and turn to the "reliable" space of principal components. The method was tested with the use of the maps of principal components for the gene pool of the East European population. Eastern Slavonic (Russians, Ukrainians, and Belarussians) and western and eastern Finno-Ugrian (Estonians and Mordovians, respectively) ethnic groups were mapped to the space of principal components. The relative positions of the populations of these ethnic groups was analyzed in the spaces of the first and the second, the first and the third, and the second and the third principal components of the East European gene pool.