Peopling, demographic history and genetic structure of the Azores Islands: Integrating data from mtDNA and Y-chromosome

Abstract

We have conducted studies to assess the variability of mtDNA and Y-chromosome markers in the Azores Islands (Portugal) and found that, for both genetic systems, the Azores, as a whole, fit well into the pattern of variation described for other Western European populations. Phylogeographic analysis of mitochondrial DNA (mtDNA) showed a major contribution from Mainland Portugal, as well as evidences of influxes from Northern Europeans, Africans and Jewish groups. Characterization of markers on the non-recombining region of the Y-chromosome (NRY) has shown a main component of European lineages as well as the presence of North African chromosomes, in frequencies similar to those described for Mainland Portugal. On the other hand, both mtDNA and NRY analyses have evidenced differential demographic histories for the three groups of islands forming the archipelago.