High degree of Y-chromosomal divergence within Finland--forensic aspects.

Among the Finns, the levels of autosomal STR and mtDNA variation have been reported to be relatively high and evenly distributed throughout the country. In contrast, the Y-STR variation is markedly lower than observed in most other European populations, showing notable geographical substructure within Finland. There are striking interregional differences--the western, middle and eastern parts of Finland segregate clearly, with phiST values comparable to the highest divergences among European populations. The low Y-STR diversity reduces the discriminative power of Y-chromosomal markers among Finns, and, furthermore, the geographical substructure complicates the assessment of profile probabilities in forensic settings. Here, the Y-STR diversity pattern in Finland is for the first time evaluated from the forensic viewpoint.