BCN, 10 June 2021.- A recent article led by Pedro Moral from the Universitat de Barcelona and Oscar Lao, head of the Population Genomics Group of the Centro Nacional de Análisis Genómico (CNAG-CRG), sheds light on the demographic dynamics of rural populations by studying the genetics of people living in the area of the Spanish Pyrenees.

Rural areas are very interesting from a population genetics point of view but also from a medical point of view because due to their history, they tend to have higher levels of inbreeding. In the Iberian Peninsula, and especially in Spain, inbreeding levels are higher on average compared to other European regions. This has been explained by both geographic and demographic phenomena. The Pyrenees are an exceptionally interesting area for studying the dynamics of rural populations since they have typically rural populations in a complex orographic environment.

“In our study we have sequenced the genome of 30 individuals corresponding to five comarques of the Catalan Pyrenees. Our analyses show differences in micro-substructure of populations within populations, although being separated by only 150 km. La Garrotxa and Ripollès tend to have more genetic similarities compared to samples from Berguedà, Alt Urgell and Pallars”, says Oscar Lao.

Using Deep Learning techniques, the researchers were able to quantify that this genetic differentiation would have taken place approximately 2,000 years ago. Compared to other Spanish samples, samples from the Pyrenees tend to present expected patterns if they have been more genetically isolated.

The study is first co-authored by Iago Maceda, who has recently obtained a PhD for this work at the Population Genomics Group of the CNAG-CRG. Raúl Tonda, Jordi Camps and Sergi Beltran from the Data Analysis Team of the CNAG-CRG have also contributed to the study.

Work of reference: Fine-scale population structure in five rural populations from the Spanish Eastern Pyrenees using high-coverage whole-genome sequence data