Fifteen millennia of human mitogenome evolution in Sicily

Sicily, situated at the heart of the Mediterranean Sea, has been a crossroads of people of different origins since the Paleolithic. To gain further insight into the genetic history of this island from a matrilineal viewpoint, we investigated 15 millennia of human mitogenome evolution. A unique Sicilian mitochondrial DNA (mtDNA) dataset, represented by 116 ancient mitogenomes (including two newly sequenced) collected from 16 archeological sites dating from 14,700 to 545 years ago, was compared with a collection of 236 modern mitogenomes covering all districts of the island. By integrating demographic modeling with phylogeographic analyses, we identified a statistically supported genetic discontinuity between the Paleolithic/Late Mesolithic and Early Neolithic periods and two mtDNA lineages (U5b and U8b/K) that specifically mark this transition. The extensive variation and lack of genetic structure among modern mitogenomes suggest the presence of a continuous, maternally inherited gene flow from different regions of Western Eurasia (since the Paleolithic) and Africa (since the Bronze Age).