An agent-based modeling framework for Out of Africa hypotheses

Ericson Hölzchen, Christine Hertler


The “Out of Africa” theory states that the genus Homo originated in Africa and from there dispersed across Eurasia. At least two different dispersal events can be distinguished. On the one hand there were the dispersals of archaic Homo such as Homo ergaster/erectus or even earlier forms which took place around 2 million years ago. We summarize these dispersals under “Out of Africa 1”. The dispersals of modern humans took place around 130 thousand years ago. We summarize these dispersals under “Out of Africa 2”. The underlying mechanisms for both dispersal events remain under debate. Currently, there are several hypotheses that try to explain these dispersal events with environmental, biological, or cognitive changes, resources and/or competition. There is currently no accepted formal representation of Out of Africa hypotheses which allows testing and comparing them on a quantitative basis. We propose agent-based modeling as an adequate method to explicitly represent Out of Africa hypotheses. An agent-based model consists of agents, an environment and rules of interaction. We apply this structure to model early hominins who interact with a Pleistocene environment. We present an agent-based modeling framework that is based on the most common Out of Africa hypotheses from literature and their associated driving factors. This framework allows the generation of testable and comparable agent-based models of various Out of Africa hypotheses and their subsequent quantification.