A study by the Catalan Pompeu Fabra University addresses the "genetic uniqueness" of the Basques, and points to the "language barrier" as a "possible bulwark" that fostered the isolation of the population in the face of the different historical events that led to contacts with other civilizations and, consequently, the confluence of cultures and languages in the rest of the peninsula.
This was the first study to explain the true origin of a population whose language, Basque, has no relation to any Indo-European language. Previously, numerous investigations had been carried out that pointed out the peculiarity of the cultural and biological traits of the Basques, but none had been able to be specified.
The study - promoted by the Pompeu Fabra University and published in the journal 'Current Biology' - has brought together an international research team to carry out the "most exhaustive geographical sampling to date", with more than 600,000 genetic markers throughout the entire genome from the DNA of the 1,970 individuals analyzed (current and from ancient times).
The results of the study - which has involved a team of linguists and geneticists- reveal that the cultural barrier of a language as different as Euskera "could promote the isolation of the Basque population from subsequent population contacts", such as the influence of the Roman Empire or the Islamic occupation of the Iberian Peninsula.
And, as they point out, the findings show a "clear differentiation" of the Basques with respect to the surrounding populations, as well as a "strong genetic heterogeneity" closely related to geography. This distinction, they say, "is the result of a genetic continuity" that dates back to the Iron Age, highly characterized by "periods of isolation and a lack of recent genetic flow, which could have been reinforced by the linguistic barrier."
The sampling included micro-regions within the Basque Country and also in the surrounding areas, this way, they obtained samples from a geographical region where Basque has always been spoken, others where it has historically been spoken but has been lost, and regions where it has never been spoken. The study covered 18 territories from the Franco-Cantabrian region.
After comparing the Basque population with other current European populations and with data from ancient DNA, they concluded that their genetic composition is similar to the rest of the Western European populations, but they present slight differences, maintained for 2,500 years due to not having mixed both with other populations. For example, they did not find influences from North Africa that is seen in most populations within the Iberian Peninsula, nor is there any trace of other migrations such as Romanization.