ABSTRACT
Migrations in prehistoric and protohistoric man are responsible for the genetic similarity observable in recent populations. As a consequence of these early migrations, small groups were founded and the resultant genetic drift and isolation were often involved in the differentiation of some populations. The Walsers of the Grisons (Switzerland) present a good example of these inter-related population-genetic phenomena: migration was the major determinant of the relatedness of the gene pool in all Walser populations. This can be proven by allele frequencies, and most convincingly by electrophoretic variants which are only shared by closely related Walser groups. This statement demonstrates clearly the congruence of the genetics and well-documented population history of the Walsers. Incidentally, blood genetic and demographic data support the hypothesis that a genetical cline exists in the valley of Safien from south to north. This is in accordance with the historical data describing the peopling of the valley by Rheinwald Walsers in the 14th to the 16th century.
