''Y chromosome variation in 457 Croatian samples was studied using 16 SNPs/indel and eight STR loci. High
frequency of haplogroup I in Croatian populations and the phylogeographic pattern in its background STR
diversity over Europe make Adriatic coast one likely source of the recolonization of Europe following the
Last Glacial Maximum. The higher frequency of I in the southern island populations is contrasted with
higher frequency of group R1a chromosomes in the northern island of Krk and in the mainland. R1a
frequency, while low in Greeks and Albanians, is highest in Polish, Ukrainian and Russian populations and
could be a sign of the Slavic impact in the Balkan region. Haplogroups J, G and E that can be related to the
spread of farming characterize the minor part (12.5%) of the Croatian paternal lineages. In one of the
southern island (Hvar) populations, we found a relatively high frequency (14%) of lineages belonging to
P*(xM173) cluster, which is unusual for European populations. Interestingly, the same population also
harbored mitochondrial haplogroup F that is virtually absent in European populations – indicating a
connection with Central Asian populations, possibly the Avars.''