摘要：The Azores archipelago (Portugal) is located in the Atlantic Ocean 1500 Km from the mainland Portugal. It is formed by nine islands of volcanic origin that define three geographical groups: Eastern, Central and Western. Flores Island, the most western and isolated of the archipelago, has unique geographic and demographic characteristics and appears to be ideal to perform genetic and biodemographic studies. In this work, we have analysed the information extracted from 6081 marriages that were celebrated from 1675 to 1880 in four parishes of Flores. The main propose is describing the marital movement in Flores and analyse the genetic structure of the island using surnames. The results obtained for the analysis of the origin of couples, endogamy/exogamy and immigration, seam to indicate that in Flores Island there are regions that have had high levels of endogamy and low levels of immigration, and others with mean values of endogamy and immigration. The results of diversity and microdifferentiation indicate that these parishes are genetically homogenous. On the other hand, the effect of the endogamy across generations combined with the low number of inhabitants could change differentially genetic frequencies in the different parishes.
