Human migrations and linkage disequilibrium ofHL-A system

A migration with admixture of genes in two populations inducesHL-A linkage disequilibrium or when gene frequencies in the two populations are dissimilar. Since theHL-A linkage disequilibrium disappears very slowly, this factor could be used to recognize some migrations. In the recent migration of American Negroes, a dilution of Caucasoid disequilibrium is noted. By the presence of values, a study of possible migrations around the world is reported and a brief comparison with other methods of research into population origins is discussed in connection with the European ecosphere: a well-known expansion axis is found from East to West (probably due to the Indo-European migration), which ends with admixture with various local Western European populations. Another expansion of genes is noted from the North of Europe towards the Southwest.