A number of recent studies have focused on the statistical properties of networked systems such as social networks and the World-Wide Web. Researchers have concentrated particularly on a few properties which seem to be common to many networks: the small-world property, power-law degree...

A deterministic trading strategy can be regarded as a signal processing element that uses external information and past prices as inputs and incorporates them into future prices. This paper uses a market maker based method of price formation to study the price dynamics induced by several...

How can new political actors may emerge from the aggregation of smaller political actors? This paper presents a simulation model that provides one answer. In its broadest perspective, the work can be seen as part of the study of emergent organization through "bottom-up" processes. In such...

We analytically study the dynamics of evolving populations that exhibit metastability on the level of phenotype or fitness. In constant selective environments, such metastable behavior is caused by two qualitatively different mechanisms. One the one hand, populations may become pinned at a local...

We examine the one-humped map at the period-doubling transition to chaos, and ask whether its long-term memory is stack-like (last-in, first-out) or queue-like (first-in, first-out). We show that it can be recognized by a real-time automaton with one queue, or two stacks, and give several new...

Wright first introduced the idea that random genetic drift and classical mass-action selection might combine in such a way as to allow populations to find the highest peak in complicated adaptive surfaces. His theory assumes large, but structured populations, in which mating is spatially local....

We study the equilibrium binding properties of multivalent ligands to cell surface receptors. In contrast to most of the previous studies, which assumed the ligand concentration to be much larger than the receptor concentration, we examine the influence on the binding properties of cell density...

The next step in the understanding of the genome organization, after the determination of complete sequences, involves proteomics. The proteome includes the whole set of protein-protein interactions, and two recent independent studies have shown that its topology displays a number of surprising...

The theory of Complex Adaptive Systems, developed within the last decade, is applied to the evolution of the ancient Hawaiian polities. A Complex Adaptive System (CAS) consists of numerous independent parts or "agents" undergoing constant nonlinear interactions. The complexity of a CAS emerges...

The First decades of the 20th century caused such an overturning of our view of the physical world, with the discoveries of relativity and of quantum mechanics, that is has tempted many laymen, historians of physics, and even physicists to assume that everything since has been merely the...