Alternative crossings into and out of Africa since 30,000 BP

Sea levels fluctuated by 125 m over the past 120,000 years, reaching their lowest during the Last Glacial Maximum (LGM) about 20,000 years ago. Globally an additional 11.6% of land area was exposed at LGM compared to today, significantly enhancing migration and travel opportunities in coastal zones. This study refines the spatial and temporal precision of ocean levels and coastlines in the Middle East by retrospectively mapping from 30,000 BP to today using an improved Glacial Isostatic Adjustment (GIA) model. We explore alternative land and sea migration routes into and out of Africa including the Suez crossing between the Red Sea and Mediterranean Sea, the Gulf of Aqaba route to the Levant, the Bab el Mandab crossing to Saudi Arabia, the crossing from Foul Bay to the Mediterranean Sea, and the island route across the Sicily and Messina Straits. The combination of DNA, archaeological evidence, and retrospective GIA mapping offers a robust reconstruction of past landscapes, aiding in the understanding of ancient human migrations and settlements in the region. Our findings favor south-to-north and east-to-west directions of sequent occupance in the Nile Valley and highlight ancient Berenice as a key port on Foul Bay based on archaeological evidence of transportation infrastructure. The unusual abundance of patch coral formations in Foul Bay raises new questions about human settlements and demands future exploration. Investigating Foul Bay’s paleogeography and archaeological remains may provide transformative insights into ancient human mobility and maritime networks.