Genetic history of the Iberian Peninsula

The ancestry of modern Iberians (comprising the Spanish and Portuguese) is consistent with the geographical situation of the Iberian Peninsula in the South-west corner of Europe, showing characteristics that are largely typical in Southern and Western Europeans. As is the case for most of the rest of Southern Europe, the principal ancestral origin of modern Iberians are Early European Farmers who arrived during the Neolithic. The large predominance of Y-Chromosome Haplogroup R1b, common throughout Western Europe, is also testimony to a sizeable input from various waves of (predominantly male) Western Steppe Herders that originated in the Pontic-Caspian Steppe during the Bronze Age.^[2][3]

Modern Iberians' genetic inheritance largely derives from the pre-Roman inhabitants of the Iberian Peninsula who were deeply Romanized after the conquest of the region by the ancient Romans:^[4][5]

• Pre-Indo-European and Indo-European speaking pre-Celtic groups: (Iberians, Lusitani, Vettones, Turdetani, Aquitani, Conii).^[6][7][8]
• Celts (Gallaecians, Celtiberians, Turduli and Celtici).^[9][8]

There are also some genetic influences from the Alans and Germanic tribes who arrived after the Roman period, including the Suebi, Hasdingi Vandals, and Visigoths.^[10][11][12] Due to its position on the Mediterranean Sea, like other Southern European countries, there were also contacts with other Mediterranean peoples such as the Phoenicians, Ancient Greeks and Carthaginians who briefly settled along Iberia's eastern and southern coasts, the Sephardi Jewish community, and Berbers and Arabs arrived during Al-Andalus, all of them leaving some North African and Middle Eastern genetic influences, particularly in the south and west of the Iberian Peninsula.^{[13][14][5][15][16][17][4]} Similar to Sardinia, Iberia was shielded from settlement from the Middle East and Caucasus region by its western geographic location, and thus has lower levels of Western Asian and Middle Eastern admixture than Italy and Greece, most of which probably arrived to Iberia during historic rather than prehistoric times, especially in the Roman period.^[18][19]