ABSTRACT
The genetic and linguistic peculiarity of the Basque population is well known. Analysis of the studies published to date on the Basque population reveals that these studies refer basically to the provinces of Vizcaya and Labourd, both in the Northern part of the Basque Country. Multidisciplinary information indicates that the landscape differences of the Basque Country could have conditioned differential population biodynamics in the Atlantic and Mediterranean parts of the Basque area. In order to evaluate this possibility, this study focuses on the genetic constitution of the Basque population of Alava (in the South of the Basque Country) through the analysis of several red-cell systems. The data obtained in this genetic study and those from archaeology, linguistics, ethnography, and skeletal biology suggest that within the "Basque population" there may be at least two distinct groups: an "Atlantic" group and a "Mediterranean" one, divided mainly by the watershed. This geographical feature could have led to a greater genetic isolation of the Northern slopes, with the South more open to population contact. This is reflected nowadays in the different cline distribution detected for most systems in the Alava Basques in comparison with other Basque and Iberian Peninsula series studied to date.
