Continental migration, not local geography, shapes the genetic adaptation of the Spanish population

The complex geographic landscape of the Iberian Peninsula has not acted as a barrier to human genetic adaptation, revealing instead that Spanish and Catalan populations share widespread adaptive signals common across continental Europe. This research leveraged an exceptionally high-quality dataset of over 800 whole genomes from the GCAT cohort, representing residents of Catalonia with ancestral roots spanning diverse regions of Spain. The findings prove that successive waves of deep historical migrations across the European continent effectively homogenized these adaptive traits over time, offering critical baseline insights into how historical demography influences modern human genetic architecture.

Reference:

Garcia-Calleja J, Biagini SA, de Cid R, Calafell F, Bosch E (2025). Inferring past demography and genetic adaptation in Spain using the GCAT cohort. Scientific Reports. DOI: 10.1038/s41598-025-98272-w