We study the simple evolutionary process in which we repeatedly find the least fit agent in a population of agents and give it a new fitness which is chosen independently at random from a specified distribution. We show that many of the average properties of this process can be calculated...

The Santa Fe Artificial Stock Market [13, 4] is an agent-based artificial model in which agents continually explore and develop expectational models, buy and sell assets based on the predictions of those models that perform best, and confirm or discard these models based on their performance...

A simple model of tag-mediated partner selection for agents playing the IPD is described. The agents strategies are represented as (i,q,q) triples as in [Nowak and May, 1992]. The tags are represented as arbitrary real numbers in [0,1], and tag selection is biased toward agents with similar...

A model of an evolving network of interacting molecular species is shown to exhibit repeated rounds of crashes in which several species get rapidly depopulated, followed by recoveries. The network inevitably self-organizes into an autocatalytic structure, which consists of an irreducible 'core'...

We introduce a method for visualizing evolutionary activity of genotypes. Following a proposal of Bedau and Packard[11], we define a genotype's evolutionary activity in terms of the history of its concentration in the evolving population. To visualize this evolutionary activity we graph the...

Evidence for somatic hypermutation of immunoglobulin genes has been observed in all the species in which immunoglobulins have been found. Previous studies have suggested that codon usage in Ig V genes is such that the sequence-specificity of somatic hypermutation results in greater mutability in...