A research team from the Institut de Biologia Evolutiva (IBE), a joint center of the Council for Scientific Research (CSIC) and Universitat Pompeu Fabra (UPF) in Barcelona, has determined that the geography of the Iberian Peninsula has not significantly influenced the genetic adaptations of the Spanish population. The study indicates that most genetic adaptations found in Spaniards are also present in other European populations and reveals no “clear set” of unique adaptive signals specific to the Iberian Peninsula, according to a statement from the IBE released on November 2, 2025.
The research examined over 800 current genomes from residents of Catalonia, aged between 40 and 60, as part of the GCAT project. The goal was to explore how historical migrations might have affected the genetic adaptations of native populations. The genomes analyzed in the GCAT project were compared to a typical Iberian genomic profile, which comprises approximately 5-10% of hunter-gatherer genomic substrate from over 6,000 years ago, 55-60% from Anatolian farmers, and 35-40% from nomadic migrations from the steppes about 4,000 years ago.
The researchers noted that while differences from the average genomic profile could conceal potential adaptive variants, the findings highlighted a considerable number of shared adaptations with other European populations, a result of extensive migrations throughout European history. Participants exhibited a typical European genetic profile, which included a small proportion of North African heritage, found exclusively in the Iberian Peninsula, southeastern France, and Sicily.
Additionally, the team investigated the French diaspora during the 16th century, which occurred as a result of the Wars of Religion. Although these immigrants constituted nearly a quarter of the population in Catalonia, the study did not identify any specific genetic footprint from this group.
New genetic variants with adaptive signatures have been discovered in current Europeans. Among these are the SMYD1 gene, which may provide increased resistance against influenza, and the FDFT1 gene, associated with cholesterol metabolism. Adaptive signals were also identified in the UBL7 gene, linked to immune response, and the rs55852693 polymorphism, associated with a higher preference for spicy foods. Furthermore, the study confirmed several well-characterized adaptations known in European populations, such as lighter skin, lactose digestion capabilities, and specific immune response traits.
