DNA polymorphisms detect ancient barriers to gene flow in Basques

Area of Science:

• Population Genetics
• Human Evolutionary Studies
• Anthropology

Background:

• The Iberian Peninsula harbors unique populations with complex genetic histories.
• Understanding the genetic landscape of autochthonous groups like the Basques is crucial for human evolutionary research.
• Previous studies have hinted at genetic heterogeneity within the Basque population.

Purpose of the Study:

• To conduct the first district-by-district genetic analysis of all Iberian provinces with autochthonous Basque populations.
• To investigate the genetic structure and historical processes shaping Basque populations.
• To explore potential correlations between genetic patterns, ancient tribes, and Basque language dialects.

Main Methods:

• District-by-district genetic analysis across Iberian provinces.
• Utilized short tandem repeat (STR) data.
• Comparative genetic analysis with neighboring populations (e.g., Aragon).

Main Results:

• Identified significant genetic heterogeneity among Basque populations.
• Populations cluster into three main groups (West, Central, East Basques), likely due to pre-Mesolithic genetic drift.
• Genetic structure appears stable along geographical axes, potentially linked to ancient tribal divisions and language dialects.
• Basque populations show genetic proximity to neighboring Aragonese populations, suggesting gene flow down the Ebro River.
• STR data indicate population structure dating back to the Mesolithic era.

Conclusions:

• Basque populations exhibit a deep-rooted genetic structure originating in the Mesolithic period.
• This genetic differentiation likely influenced the formation of ancient tribes and Basque language dialects.
• Findings support the hypothesis that Neolithic period played a significant role in shaping modern European genetic diversity.
• Evidence suggests gene flow from the Basque region towards the Mediterranean via the Ebro River valley.