PP042-03
Human ancestors’ dispersal: the role of climate
Tuesday, 15 December 2020: 05:36
Virtual
Gilles Ramstein1, William Banks2, Doris Barboni3, Olga Otero4, Pierre Sepulchre1, Camille Contoux1, Frederic Fluteau5, Masa Kageyama1, Christophe Dumas6, Ning Tan7, Yannick Donnadieu6, Jean-Renaud Boisserie8, Florence Sylvestre9, Gildas Merceron10, Anne Delagnes11, Geraldine Garcia12, Olivier Chavasseau13, Francesco d'ERRICO14, Antoine Souron11 and Corentin Gibert15, (1)LSCE Laboratoire des Sciences du Climat et de l'Environnement, Gif-Sur-Yvette Cedex, France, (2)PACEA De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie, Bordeaux, France, (3)CEREGE Centre de Recherche et d'Enseignement de Géosciences de l'Environnement, Aix en Provence, France, (4)IPHEP Institut International de Paléoprimatologie, Paléontologie Humaine : Evolution et Paléoenvironnement, Poitiers, France, (5)Institut de Physique du Globe de Paris, Paris, France, (6)LSCE CEA/CNRS, Gif Sur Yvette, France, (7)Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences,, Beijing, China, (8)CNRS, University of Poitiers, Institut de Paléoprimatologie, Paléontologie Humaine : Évolution et Paléoenvironnements, Poitiers, France, (9)CEREGE, Aix-en-Provence Cedex, France, (10)PALEVOPRIM : Laboratoire Paléontologie Evolution Paléoécosystèmes Paléoprimatologie, Poitiers, France, (11)PACEA : De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie, Bordeaux, France, (12)IPHEP : Institut de paléoprimatologie et paléontologie humaine : évolution et paléoenvironnements, Poitiers, France, (13)IPHEP : Institut de paléoprimatologie et paléontologie humaine : évolution et paléoenvironnements., Poitiers, France, (14)PACEA : De la Préhistoire à l’Actuel : Culture, Environnement et Anthropologie, Bordeaux, France, (15)PALEVORPIM : Paléontologie Evolution Paléoécosystèmes Paléoprimatologie, Poitiers, France
Abstract:
Thanks to an ANR French program we built a multidisciplinary consortium called HADOC: “Human ancestors’ dispersal: the role of climate”. Techniques within this group include climate and niches models, as well as climate and environment reconstruction both in terms of flora and fauna and paleontological data.
The major questions are: how far tectonics and climate evolution may explain Apes dispersal from 23 to 7 Ma, and the migrations of Australopithecus in Africa from 7 to 2 Ma.
To tackle these questions we reconstruct the paleogeography of key periods: Early Neogene EN (23 Ma), Mid Miocene Climate Optimum MMCO (16 Ma), Miocene Climate Transition MCT (14 Ma), Early Tortonian ET (11 Ma) and Late Tortonian LT (7 Ma) and finally Mid Late Pliocene MLP (3 Ma).
Regarding the first question, because Apes are dependent on the tropical forest, we use vegetation models in order to simulate the extant of this biome from 23 to 7 Ma.
Earlier studies performed with simple GCM (FOAM) showed the extent of tropical forest to Europe during the MMCO (Hamon, Geology, 2012) and the impact of the east-Tethys seaway during the MCT (Hamon, Clim. Past., 2013).
Concerning the dispersal of Australopithecus from 7 to 3 Ma we will study the behavior of the west African monsoon and its potential extent to Central Africa during wet periods correlated with the Mega Lake Chad (Contoux et al., Clim. Past., 2013).
Our approach consists in using simulations carried out with the IPSL earth system model downscaled to 50 km, and then to use niches modeling to diagnose the potential areas of dispersal (d’Errico, PNAS, 2017). Superimposed to 5 references simulations from Miocene to Pliocene we will provide sensitivity experiments to different factors (geologic ones, orography of mountain ranges, seaways and astronomical variations - especially for monsoon evolution).
