Before revision:  In this paper we discuss the Gaiahypothesis and the idea of sequential selection. Building on previous work using the Tangled Nature Model of co-evolution we elaborate on Gaia as an example of an entropic hierarchy.
After revision:  In this paper we discuss three mechanisms which could potentially lead to Gaia: Selection by Survival, Sequential Selection and Entropic Hierarchy. We use the Tangled Nature Model of co-evolution we elaborate on Gaia as an example of an entropic hierarchy.