El impacto del estrecho de Gibraltar y su entorno sobre la diversidad genética humana en el Mediterráneo occidental

Abstract

Present-day western Mediterranean human populations have traditionally been one of most thoroughly studied, in the world, from its archeology to its genetic diversity. The Mediterranean Sea represents a unique geographic space. This singularity is due to its role as an intercontinental sea. The Strait of Gibraltar is the western border of the Mediterranean and it is also the closest point between Africa (Morocco) and Europe (Iberian Peninsula). The present work aims to provide some genetic results that reveal that the Strait and its surroundings have represented an important and ancient geographic corridor for migration routes between Africa and the Iberian Peninsula along recent human history. The most visible evidences on the complexity of human contacts across the Strait of Gibraltar maritime zone have appeared from studies based on uniparental markers (mtDNA and Y-C) and, more recently, from high-throughput genotyping of the human genome. Data have been convergent to show that the most intense African genomic traces within Europe are concentrated at the Iberian Peninsula, mainly along its southwestern geographical fringe. This scenario allows confirming the key role of the Strait of Gibraltar for human movements, which are not easily reconcilable with historical events. Genomic studies performed in populations from both sides of the Strait have shown that from early Holocene times (Mesolithic) (10.700 cal BP or 9.500 BC) onwards, African incoming groups began to leave signatures into the Iberian genomes. Human mobility in the region has been recurrent, reciprocal and non-sporadic.