Y‐chromosome lineages in São Tomé e Príncipe islands: Evidence of European influence

The Y‐chromosome haplogroup composition of the population of São Tomé e Príncipe (STP) archipelago was analyzed using 25 biallelic markers and compared with populations of different origins from Europe, Africa, and the Middle East. Two main Y‐chromosome haplogroups were found: E3a, very common among sub‐Saharans accounts for 84.2% of the paternal lineages and R1b, typical of West Eurasia, represents 8.7% of the overall male population. Nevertheless, we detected in the population of STP a significant heterogeneous distribution of R1b among the two main ethnic groups of the archipelago: Forros (10.3%) and Angolares (6.6%). Together, haplogroups known to be prevalent in West Eurasia reach 12.5% of the chromosomes analyzed unequally distributed among the two groups: Forros present 17.7% while Angolares display only 8.2% of west Eurasian haplogroups. Our findings suggest that, despite its sub‐Saharan genetic background, a relevant contribution of European paternal lineages is present in nowadays STP population. This influence has shown to be stronger in Forros than in Angolares , which could be explained by the social isolation that these have last experienced through their history.Am. J. Hum. Biol. 19:422–428, 2007. © 2007 Wiley‐Liss, Inc.