Factors related to inbreeding components from isonymy in an urban population: Aranjuez (Spain)

An isonymic analysis has been carried out using a sample of 1529 reconstituted families residing during 1870-1964 in Aranjuez, an urban area situated south of Madrid, Spain. The random, non-random and total-components inbreeding coefficients from isonymy were obtained and the various combinations of surnames compared in order to infer the patri- or matrilocal pattern of residence. Throughout the period studied the random component of inbreeding (F(r)) has not changed, in contrast to the non-random component (F(n)), thus suggesting the latter could be responsible for the reduction of total inbreeding. Using several methodological approaches (biplot analysis, alpha, nu and percentage of immigrants) the predominance of the immigration of grooms was interpreted in terms of Aranjuez as a matrilocal pattern of residence. From this study it can also be concluded that surnames provided by reconstituted families are good estimators of inbreeding and migration.