Why are some ecosystems so rich, but yet contain so many rare species? High species diversity, together with rarity, is a general trend in neotropical forests and coral reefs. But the origin of such diversity and the consequences of food web complexity in both species abundances and temporal...

In the study of complex systems---in particular self-organizing systems---the notions of emergence and higher order structures come up. A framework for studying them was given in [1,2] where the notion of a hyperstructures occur both in an intuitive and a formal sense. But in formalizations of...

Complex, fractal structures are widespread in ecological systems and in some characteristic features of evolutionary processes. The origin of such patterns in terms of their dynamics is a challenging problem. A theory for these phenomena might have important implications in issues like the...

Highly optimized tolerance is a model of optimization in engineered systems, which gives rise to power-law distributions of failure events in such systems. The archetypal example is the highly optimized forest fire model. Here we give an analytic solution for this model which explains the origin...

The dynamics of origination in the fossil record of three marine groups (molluscs, echinoderms and fishes) and three terrestrial groups (mammals, insects and plants) is analyzed in this paper. Four hypotheses are tested: (1) secular decline in lineage origination; (2) secular decline in...

"Glider" dynamics in cellular automata (CA), where coherent configurations emerge and interact, provide a stark instance of self-organization in a simple system. Such behaviour was classified as class 4 or complex (as opposed to ordered or chaotic) by Wolfram, and was one of the original...

Self-organizing maps (SOM) are unsupervised, competitive neural networks used to project high-dimensional data onto a low-dimensial space. In this article we show how SOM can be sued to draw graphs in the plane. The SOM-based approach to graph drawing, which belongs to the general class of...

How are biodiversity dynamics developmentally constrained at various hierarchical levels? Patterns of diversity and associated process theories have conventionally been treated in extrinsic, particularly ecological, terms, and development has not been sufficiently integrated into discussions of...

In previous papers (Theraulaz et al. 1995, Bonabeau et al. 1996) we suggested, following Hogeweg and Hesper (1983, 1985), that the formation of dominance orders in animal societies could result from a self-organizing process involving a double reinforcement mechanism: winners reinforce their...

Self-organization was originally introduced in the context of physics and chemistry to describe how microscopic processes give rise to macroscopic structures in out-of-equilibrium systems. Recent research, that extends this concept to ethology, suggests that it provides a concise description of...