Impact of wars on the evolution of civilizations

Throughout the evolutionary track of human, the evolution or extinction of both ancient and modern civilizations are characterized by processes like growth, assimilation, invasion, aggression, and annihilation. How did human civilizations evolve through wars and assimilations as envisaged in history? Here we perform a set of simple in silico experiments in two space dimensions where different group of domains (civilizations) each of different sizes are allowed to evolve through interactions (wars) and coalescences from their initial random distribution. As they grow in size, domains of similar group undergo coalescence when they meet while domains belonging to different group engage in warfare at the point of interaction. During a warfare, the smaller domain is annihilated and the larger domain shrinks in size depending upon the fairness of the war. As a result, we obtain varying decay rate and age-size distribution of civilizations under different conditions and they are found to depend on the fairness of war, initial distributions, number of distinct groups, and initial number density. We also investigate the impact of war in the presence of powerful civilizations that never retreats in a war. By tuning the critical size for an autonomous civilization, we show in accordance with the historical fact that the primitive period is quite longer with a very high frequency of war than the post-primitive period that starts from the very beginning of the autonomous civilization. We discuss several issues related to the extinction and persistence of civilizations in the light of some existing historical data. (C) 2019 Elsevier B.V. All rights reserved.