摘要：Surnames have frequently been used in the study of the genetic structure of human populations through various methods. An ample bibliography exists on isonymy referring to diverse regions and countries with different transmission systems of surnames among generations. Several authors have considered differently the available information included in ecclesiastical archives concerning Portugal. Nominal analyses have occasionally been based on the present transmission system of surnames; however, some authors have indicated that these norms did not apply during recent centuries. The objective of the present study is to determine which system of transmission of surnames better corresponds to Portugal at the end of the 18th century, and evaluate the use of surnames for studies of isonymy in this country. For this purpose, a data base was used from marriage certificates of the parishes of Olivenza (Badajoz) in the period 1750-1801, when this location was under Portuguese sovereignty. By means of an analysis of frequencies, the concordance between surnames of grooms and brides with those of their parents was evaluated. A highly probably rule of surname transmission was identified. In order to test the goodness of the study of isonymy in Portugal the use is proposed of the first surname of the groom and the first surname of the father of the bride due to their higher frequency and because of the tested transmission among generations.
