The spread of steppe and Iranian-related ancestry in the islands of the western Mediterranean

Steppe-pastoralist-related ancestry reached Central Europe by at least 2500 bc, whereas Iranian farmer-related ancestry was present in Aegean Europe by at least 1900 bc. However, the spread of these ancestries into the western Mediterranean, where they have contributed to many populations that live today, remains poorly understood. Here, we generated genome-wide ancient-DNA data from the Balearic Islands, Sicily and Sardinia, increasing the number of individuals with reported data from 5 to 66. The oldest individual from the Balearic Islands (~2400 bc) carried ancestry from steppe pastoralists that probably derived from west-to-east migration from Iberia, although two later Balearic individ…