Theory Building with System Dynamics: Ice Age Extinctions

摘要

A recently developed system dynamics model specifies a new hypothesis for the extinctions at theend of the Pleistocene – Second Order Predation – and compares it with the overkill hypothesis(see http://quaternary.net/extinct2000). It provides a quantitative description of theinterrelationships between four plant stocks, four herbivore stocks, carnivores, and H. sapiens.Different assumptions regarding H. sapiens in-migration, hunting of prey or predators, can besimulated. Second Order Predation: i.e. H. Sapiens killing of other carnivores, leads to herbivoreoverpopulation, environmental degradation, and differential extinction of herbivores. The papersuggests thinking about whole system evolution and calls for additional models that will supportcomparison of competing hypotheses, allow precision in quantities and timing, and exhibit internaldynamics. It challenges scientists conversant with models to simplify models to encourage their useby their colleagues.