Résumé
Significance The Initial Upper Paleolithic (IUP) marks a distinct cultural change possibly related to Homo sapiens dispersals into Eurasia. New radiocarbon and optically stimulated luminescence dates from the recent excavations at Boker Tachtit, Negev, Israel, show that the IUP starts as early as around 50,000 y ago, and the later IUP phase dates to 48,000 y ago. Thus, the Late Middle Paleolithic (MP) and early IUP populations both inhabited the Negev 50,000 y ago. The Negev later IUP phase and the Early UP of the Eastern Mediterranean woodland are contemporaneous. These results also show that the MP to UP transition was a fast-evolving process.