Article: Macroevolution in silico: scales, constraints and universals

Large-scale evolution involves several layers of complexity spanning multiple scales, from genes and organisms to whole ecosystems. In this article, we review several models involving the macroevolution of artificial organisms, communities or ecosystems, highlighting their importance and potential role in expanding the Modern Synthesis. Afterwards, we summarize the key results obtained from our model of artificially evolved ecosystems where individuals are defined as embodied entities within a physical, simulated world where they can evolve different traits and exploit multiple resources. Starting from an initial state where single cells with identical genotypes are present, the system evolves towards complex communities where the feedbacks between population expansion, evolved cell adhesion and the structure of the environment lead to a major innovation resulting from the emergence of ecosystem engineering. The tempo and mode of this process illustrates the relevance in considering a physical embedding as part of the model description and the feedbacks between different scales within the evolutionary hierarchy. The future steps in modelling macroevolution by means of in silico models and how they might contribute to the Modern Synthesis are outlined.