Early Gravettian genomic data from Western Europe reveal population movements before the LGM

Anatomically modern humans first settled in Europe at least 45,000 years ago, yet limited genomic data from 45 to 20 thousand years (ka) constrain reconstructions of Upper Palaeolithic population dynamics. Before the Last Glacial Maximum (LGM; ∼26.5 to 19 ka), Gravettian groups (∼34 to 25 ka) were widespread across Europe and genetically diverse, including the Fournol and Věstonice lineages. Here, we present genome-wide data from three Gravettian individuals: two from the Franco-Cantabrian region (Chufín, Spain, and Isturitz, France) and one from Italy (Ostuni1b). Our analyses reveal previously undetected gene flow between eastern and western early Gravettian populations in southwestern Europe, challenging models of regional genetic continuity from the Aurignacian to the Solutrean (∼24 to 19 ka). To investigate population history during the LGM, a period for which human skeletal remains are extremely rare, we analyzed sedimentary ancient DNA from Solutrean Layer 122 at El Mirón Cave (Cantabria, Spain; ∼22,000 calibrated years before the present), recovering ∼14,000 human single-nucleotide polymorphisms. These data support persistence of Fournol-related ancestry in southwestern Europe throughout the LGM.