[M-IS14] Paleoclimatology and paleoceanography

[MIS14-03] Paleoclimate archives document an arduous life on the journey from Africa in the Last Interglacial era

★Invited Papers

*Watanabe Takaaki^1,2,3, Miriam Pfeiffer¹, Atsuko Yamazaki^2,7, Dieter Garbe-Schönberg¹, Hsun-Ming Hu^4,5, Chuan-Chou Shen⁴, Saori Ito¹, Tsuyoshi Watanabe^2,3,6 (1.Christian-Albrechts-Universitaet zu Kiel, 2.KIKAI Institute for Coral Reef Sciences, 3.Hokkaido University, 4.National Taiwan University, 5.The University of Tokyo, 6.Research Institute for Humanity and Nature, 7.Nagoya University)

Keywords:Human dispersal, Human evolution, Thermal stress, Coral, Last Interglacial Period, Arabian Peninsula

Homo sapiens, dispersing from Africa, reached the Arabian Peninsula and the Levant before the Last Interglacial Period (LIG, 117,000~127,000 years ago, early dispersal wave). For this early dispersal from Africa, two routes are proposed: a northern route through the Nile Valley corridor to the Sinai Peninsula and a southern route along the southern Arabian Peninsula coast. During the LIG, wet/vegetated environments were formed along both routes, which were considered suitable habitats for Homo sapiens after dispersal out of Africa. However, despite wet conditions, LIG dispersals to Europe and Asia were limited for unclear reasons. Here, we estimate the human habitability in LIG environments along the dispersal routes based on a human physiological model and climate patterns that a single human would have encountered during its lifetime. We provide new monthly-resolved Oman coral data from the LIG to reconstruct the seasonal climatic variations along the southern route. The published fossil coral record from the northernmost Red Sea is used to represent the northern route climate. By comparing two coral records with the climate model, we obtained the climate patterns in LIG. Our results reveal summer in the northern route was relatively mild during the LIG, which could have provided a refugium for Homo sapiens. On the other hand, in the Arabian Peninsula, temperature seasonality increased with prolonged hot summer seasons due to weak monsoonal cooling coupled with enhanced summer insolation. The human physiological model shows this summer heat in the Arabian Peninsula limited human habitability, despite wet/vegetated environments. We conclude that extreme summer heat during the LIG could have been the primary barrier hindering the early dispersal beyond/crossing the Arabian Peninsula.