A recent study conducted by a team from the Institut de Biologia Evolutiva (IBE), a collaborative center between the Consejo Superior de Investigaciones Científicas (CSIC) and the Universitat Pompeu Fabra in Barcelona, has revealed that the geography of the Iberian Peninsula has not significantly influenced the genetic adaptations of the Spanish population. This research, announced on November 2, 2025, emphasizes that most genetic adaptations observed in Spaniards are also present in other European populations, lacking a distinct set of adaptations unique to the Iberian region.
The investigation analyzed over 800 contemporary genomes from residents of Catalonia, aged between 40 and 60 years, as part of the GCAT project. The aim was to understand how historical migrations shaped the genetic landscape of native Spaniards. Findings indicated that the typical Iberian genomic profile includes approximately 5-10% ancestry from hunter-gatherers dating back over 6,000 years, about 55-60% from Anatolian farmers, and 35-40% from nomadic migrations from the Steppes approximately 4,000 years ago.
Researchers pointed out that while differences from the average Iberian genome may hide potential adaptive variants, the results predominantly show shared adaptations with other European populations, attributed to extensive migrations throughout European history. The genetic profile of the participants reveals a typical European background with a small fraction of North African ancestry, which is unique to the Iberian Peninsula, parts of southeastern France, and Sicily.
Additionally, the study examined the impact of the 16th-century French diaspora, which occurred during the Religious Wars. Although these immigrants constituted about a quarter of the Catalan population at one point, the study found no specific genetic trace from this migration.
Among the significant discoveries were new genetic variants associated with adaptive traits in modern Europeans, including the gene SMYD1, which may enhance resistance to influenza, and FDFT1, related to cholesterol metabolism. The research also identified adaptive signals in the gene UBL7, linked to immune response, as well as the polymorphism rs55852693, which is associated with a preference for spicy foods. Furthermore, the study confirmed several well-characterized adaptations in European populations, such as lighter skin, lactose digestion capability, and specific immune response traits.
