RT Journal Article T1 Lactase Persistence in Southern Iberia and Northwestern Africa: New Insights into the Population Structure and History of the Western Mediterranean A1 Calderón Fernández, María Del Rosario A1 Hernández De La Fuente, Candelaria Lucía A1 Sánchez Martínez, Luis Javier A1 Cabau, Javier A1 Novelletto, Andrea A1 Dugoujon, Jean-Michel A1 Pereira, Luisa AB The development of lactose tolerance in humans represents a fair example of interaction between biology and culture. Lactase persistence (LP) during adulthood is strongly associated with several genetic variants (SNPs) in the MCM6 region (2q21.3). The −13910 C/T is the most widely analysed variant in present-day human populations and its origin has been postulated in central Europe during the Neolithic. To deepen the knowledge on the incidence of LP trait in the western Mediterranean, a number of 470 adult individuals autochthonous from southern Iberia and north-western Africa (Mo- rocco) were genotyped for the SNPs −13907 C/G, −13910 C/T, −13915 T/G, and −14010 G/C related to LP phenotype. Allele and genotype frequencies were estimated as well as proportions of predicted LP phenotype. Besides, contour maps based on allele frequencies were constructed, and a Bayesian Model was implemented in order to analyse the geographic distribu- tion patterns of LP trait and associated mutations across Europe, Africa, Mediterranean Basin and neighbouring areas. Frequencies of the European −13910*T derived allele among southern Iberian populations reached a mean value of 0.418 whereas in Moroccan Berbers figures were comparatively lower: 0.092 (Bouhria), 0.175 (Figuig) and 0.188 (Asni). The −13915*G variant, with a probable origin in the Arabian Peninsula, was observed in the study of Moroccan Berber samples (not in the Iberia Peninsula) with frequencies varying between 0.025 (Asni) and 0.066 (Bouhria). The Bayesian model provided a frequency value for LP trait in the Iberian Peninsula of 0.615 (95% PI: 0.594 – 0.636) whereas in the Maghreb it was 0.313 (95% PI: 0.275 – 0.352). Our results give further support to an European origin for −13910*T allele, and unveils a negative gradient of its frequencies from Iberia towards Maghreb, giving evidence again to the recurrent prehistoric and historical human movements and admixture processes through the Gibraltar Strait and its adjacent coasts. PB Croatian Anthropological Society SN 0350-6134 YR 2019 FD 2019 LK https://hdl.handle.net/20.500.14352/98063 UL https://hdl.handle.net/20.500.14352/98063 LA eng NO Calderón, R., Hernández, C. L., Sánchez-Martínez, L. J., Cabau, J., Novelletto, A., Dugoujon, J.-M., & Pereira, L. (2019). Lactase Persistence in Southern Iberia and Northwestern Africa: New Insights into the Population Structure and History of the Western Mediterranean. Collegium Antropologicum, 43(2), 81–92. NO Ministerio de Economía y Competitividad (España) NO Portuguese Foundation for Science and Technology NO European Commission DS Docta Complutense RD 8 abr 2025