Genetic affinities of the Shetland islanders.

Phenotype and gene frequencies in blood group, red cell enzyme, and serum protein polymorphisms in a sample of Shetland islanders are reported. Analyses of genetic distance and relationship indicate that Shetland affinities are closer to nearby populations bordering the North Sea rather than to those of the North Atlantic. The closest affinities seem to be with populations in north Britain with a similar history of Norse influence. There is evidence that the Shetlanders retain an element of an ultra-European population extreme in some gene frequencies and so, like the Orcadians, may be regarded as much diluted relict of an ancient population.