Emergence through mutations, selection, and adaptation: The Tangled Nature model of evolutionary ecology

At the most basic level evolutionary dynamics consists in agents which reproduce and die. The offspring may differ from the parents due to random mutations. The Tangled Nature (TaNa) model study the consequences of this dynamics in the case where the different types of cp-existing agents influence each other’s reproduction rate. This simplest of dynamical assumptions is able to generate a universe of evolved ecosystems that possess many features observed in nature including the gradual decrease in the overall extinction rate since the Cambrian explosion, lognormal-like Species Abundance Distributions, power law-like Species Area relationships and more.

 The model is individual based and allow us to study emergent collective aspects of evolutionary dynamics. The long-time dynamics show similarity with glassy dynamics and exhibits intermittency with abrupt transitions (macro-extinctions). This can be seen as a result of systemic adaptation which produces networks of types of agents with beneficial interaction structure. Long standing question concerning the level of selection: individual versus group or hierarchical selection can addressed by applying information theoretic methods to study agency at different scales.