AI interpretationAI-generated
Ancient DNA from western Mediterranean islands reveals steppe, Iranian and African gene flow.
This study sequenced ancient genomes from the Balearic Islands, Sicily and Sardinia, expanding data from 5 to 66 individuals. It shows that steppe pastoralist ancestry reached the Balearics by 2400 BC and Sicily by 2200 BC, while Iranian-related ancestry arrived in Sicily by the mid-second millennium BC. Sardinia remained largely descended from early farmers until the first millennium BC, with a Chalcolithic outlier of North African ancestry. Later, major immigration into Sardinia began in the first millennium BC, reducing early farmer ancestry to 56-62%.
- Steppe pastoralist ancestry reached the Balearic Islands by ~2400 BC, likely via west-to-east migration from Iberia.
- Iranian-related ancestry arrived in Sicily by the mid-second millennium BC, and Sicily saw large-scale population replacement after the Bronze Age.
- Sardinia was largely descended from early farmers until the first millennium BC, but later immigration reduced that ancestry to no more than 56-62%.
Sample interpretation
The site samples include two individuals with resolved Y-chromosome lineages: R-Z195 and E-V1039. Their mitochondrial DNA types are U8b1b1 and M1a1b1. These lineages are consistent with the diverse ancestries described in the paper, including steppe-related and North African connections, though the small sample size limits broader conclusions.
For genealogy enthusiasts
For ancestry enthusiasts, this study shows that western Mediterranean islands were not isolated but shaped by repeated migrations from Iberia, the Aegean, and North Africa. It highlights how ancient DNA can reveal complex population histories even on islands.
Abstract
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 individuals had less ancestry from steppe pastoralists. In Sicily, steppe pastoralist ancestry arrived by ~2200 BC, in part from Iberia; Iranian-related ancestry arrived by the mid-second millennium BC, contemporary to its previously documented spread to the Aegean; and there was large-scale population replacement after the Bronze Age. In Sardinia, nearly all ancestry derived from the island’s early farmers until the first millennium BC, with the exception of an outlier from the third millennium BC, who had primarily North African ancestry and who—along with an approximately contemporary Iberian—documents widespread Africa-to-Europe gene flow in the Chalcolithic. Major immigration into Sardinia began in the first millennium BC and, at present, no more than 56–62% of Sardinian ancestry is from its first farmers. This value is lower than previous estimates, highlighting that Sardinia, similar to every other region in Europe, has been a stage for major movement and mixtures of people.