Authors

Carolina Cucart-Mora¹; Kamilla Lomborg⁵; Jan-Olaf Reschke¹³⁴; Harry Hall¹²; Mehdi Saqalli⁵; Christine Hertler⁴; Matt Grove²; Marie-Hélène Moncel¹

¹CNRS UMR 7194 HNHP, National Museum of Natural History, Institut de Paleontologie Humaine, Rue René Panhard, 75013 Paris, France.

²Department of Archaeology, Classics and Egyptology, University of Liverpool, 8-14 Abercromby Square, Liverpool L69 7WZ, UK.

³Institute for Ecology, Evolution and Diversity, Goethe University, Frankfurt am Main, Germany.

⁴ROCEEH Research Center, Senckenberg Research Institute, Senckenberganlage 25, 60325 Frankfurt am Main, Germany. ⁵CNRS UMR 5602 GEODE Géographie de l'Environnement, Maison de la Recherche, Université Toulouse 2 Jean Jaurès, 5, Allées Antonio Machado 31058 Toulouse, France.

Abstract

Understanding the ecological dynamics of the earliest occupations out of Africa, and how they affected the occupation of new territories in Eurasia, is an especially challenging archaeological endeavour. Being aware of it, the Lateurope ERC project devotes a whole work package to reconstructing these dynamics and model how different hominin populations interacted with them in Eurasia between 1.5 and 0.5 million years ago. In this paper, we present the working hypotheses, data management protocols, modelling strategies and expected results of this work package. 

 The earliest evidences of the presence of hominins out of Africa are documented in Eurasia, and are dated to around 2.1 million years in China, and 2 million years in the Levant. Although the presence of hominins is documented in southern Caucasus 1.8 Ma ago, the first evidences of hominin presence in Western Europe are dated to around 1.4 million years ago in Southern Europe. Thus, according to available archaeological data Western Europe remained at the limit of the human “Oikoumene” for almost 1 million years. To explain the delay in the occupation of Western Europe, we consider three hypotheses: i) the current pattern may be the result of taphonomic bias, ii) the climatic, geographical, or environmental conditions of Europe may have hindered the dispersion and settlement of populations in sufficient numbers and of sufficient duration to be archaeologically visible, also by closing the ecologically suitable corridors., and iii) specific cognitive capabilities may have been necessary for hominins to successfully occupy this area.

 The occupation of Western Europe continues raising questions. The archaeological record from the Early and Middle Pleistocene is relatively sparse and has a very low chronological resolution. This makes it difficult for archaeologists to understand the complex hominin ecology and process of colonization. In our project we have opted for an interdisciplinary approach, bringing together specialists in archaeology, ethnography, biology and climatology, to apply different computational modelling techniques to broaden and deepen the understanding of this process. 

The first step was the compilation of a database that includes all archaeological evidences of hominin presences between 1.5 and 0.4 million years. This information is complemented with information about the hominins’ technological and subsistence behaviour elaborated by archaeologists within the project. Establishing the quantity and quality of available data is essential as it will be used during the construction, parametrization and validation of the different models. The modelling task will start with the first steps for a paleoenvironmental reconstruction of Eurasia across time, and establishing the niche of different hominin populations. Subsequently, this information will be used as part of four agent-based models designed to understand different spheres of hominin-environment interactions that interplay at different temporal and spatial scales. 

The first agent-based model aims to reconstruct evolving Eurasian ecosystems over time and hominins response to them, and consist of two modules: one representing the reconstructed ecosystems, and the other one simulating population survivability, reproduction capacity, and dispersals according to each pixel ecosystem dynamics. The second model will analyse how hominin subsistence and mobility patterns adapted to different climatic conditions within ecosystems (i.e., glacial vs. interglacial). Initially, the model will simulate a single group subsisting in three ideal environments corresponding to different latitudes (i.e., biomes). Subsequently, complexity will be increased by introducing competition for resources among groups and greater environmental variability. The third model has a dual objective: to understand the emergence of behavioral plasticity in relation to climatic and environmental oscillations and how this feature may have favored the occupation of Western Europe. The fourth model, called the Central Mode, is going to integrate the impact of environmental and geographical barriers, the emergence of new behaviors in Western Europe and their influence in the occupation process. 

The integration of the three sub-models, into the large-scale model will be done in three phases, gradually increasing its complexity. The first phase will involve a simple reactiondiffusion model in which population dispersion is a function of population growth. The second phase will incorporate, if deemed necessary, the range of variability observed in the subsistence and mobility sub-model. Finally, the lessons learned about the emergence of behavioral plasticity and/or the advantages that they may have granted to hominins will be included. The agent-based model will be validated by comparing the speed and direction of the population advance with the earliest dates of occupation in the different regions of Eurasia. The outputs of the central model will be analysed with the aim of identifying the relevant dynamics/variables to explain the current spatiotemporal pattern of the occupation of Western Europe. With this interdisciplinary modelling approach, we expect to overcome the limitations posed by the archaeological record and help validate the hypotheses considered by the Lateurope project.