Exploring paleo food-webs in the European Early and Middle Pleistocene: a network approach

Abstract

Food webs are networks of feeding (trophic) interactions among species. As any other network approach, research on food webs focuses its analysis on the structure of direct and indirect interactions among diverse species, rather than looking at the particularities of certain taxa. In recent times, scholars have collected an impressive amount of empirical food-web data to study present day terrestrial and aquatic habitats. Moreover, there is an increasing literature on the construction of theoretical models of food-web structure to understand dynamics of ecological communities (for instance, robustness to the extinction of certain species or introduction of new ones). This approach has also been applied to trophic interactions represented in the fossil record of extinct ecosystems. Since the seminal paper by Dune et al. on Cambrian food-webs, several authors have reconstructed and/or modeled paleo or fossil food-webs. Nevertheless, to our knowledge, none of them has addressed the role played by the different Pleistocene hominin species as part of such food-webs. In this work, we aim at filling this gap (at least, partially) by focusing on the Early and Middle Pleistocene paleocommunities in Western Eurasia. Our goal is to improve our understanding on changes experienced by large mammals’ interactions during this period, and shed some light on the influence of and on Homo species of those changes. We have constructed up to 25 paleo food-webs from the archaeo-paleontological record of European assemblages, covering from the Middle Villafranchian to the Late Galerian. Only large mammals have been considered, including a couple of Homo species that are present in 10 food-webs. In order to address our research questions, we will develop a two-steps analysis. First, we will calculate the main structural features of all the networks, and compare them across geographical areas, periods and cases with and without Homo species. Second, we will perform computational experiments on the obtained networks (and, eventually, also on synthetic ones generated from theoretical models) focusing on dynamical aspects of hominin interactions with other large mammals.