Isonymic structure of the Argentine Northwest.

Surname distribution may be used as a substitute for quantitative information on the genetic structure of human populations due to panmictic deviations. This study analysed the isonymic structure of the Argentine Northwest (ANW) populations. Surname distribution of 2,576,548 voters (year 2001) in the 117 departments of the region was analysed. Fisher's alpha and coefficient of random relationship by isonymy were estimated. A dendrogram of the 117 departments was constructed from the matrix of Euclidean distances. In general, alpha values found were lower than country averages, while kinship values were higher. Ten clusters were identified showing a spatial distribution closely related to geographic characteristics, means of communication, and location of economic activities of the region. The resulting pattern could be basically characterized by grouping the departments into two large clusters: (a) Those located in the centre of the region, which include the provincial capitals, presented greater diversity of surnames and a lower degree of kinship. (b) Those located in the regional periphery showed greater isolation and kinship. Isonymic parameters estimated agree with the demographic characteristics of populations, historical antecedents of population settlement and ANW geographic features.