Mutation is introduced into autocatalytic reaction networks. The differential equations obtained are neither of replicator type nor can they be transformed straightway into a linear equation. Examples of low dimensional dynamical systems---$n= 2, 3 $, and 4---are discussed and complete...

The mean number (N) of metastable states in higher order short-range spin glasses is estimated analytically using a variational method introduced by Tanaka and Edwards for very large coordination numbers. For lattices with small connectivities, numerical simulations do not show any significant...

A model in which heterogeneous agents form firms is described and empirically tested. Each agent has preferences for both income and leisure and provides a variable input ('effort') to production. There are increasing returns to cooperation, and agents self-organize into productive teams. Within...

Shapes of biological macromolecules---RNA, DNA, and proteins---can be represented by abstract algebraic structures provided as suitably coarse resolution is chosen. These abstract structures, for instance partially ordered sets and permutation groups, can be used for deriving new metric...

Artificial Life and the more general area of Complex Systems does not have a unified theoretical framework although most theoretical work in these areas is based on simulation. This primarily due to an insufficient representational power of the classical mathematical frameworks for the...

The fossil record of insects documents a high proportion of modern higher-level taxa (67% for families), although this capture rate drops off considerably for lower-level taxa. This record is Lagerstatten-driven, and is deployed by complementary, parallel body- and trace-fossil components that...

It is often taken for granted that as systems evolve over time they tend to become more complex. But little is understood about the mechanisms that might cause evolution to favor increases in complexity over time. This paper proposes three means by which complexity tends to grow as systems...

The immune system uses many strategies to generate its enormous repertoire of diverse antibodies, but their relative importance is not understood. As part of a larger project to quantify their relative contributions, we have studied how the survival probability of an individual scales with the...

In the information contagion context, agents choose sequentially between two competing products, basing their decisions upon information obtained from a sample of previous adopters. The market shares that each product obtains depend upon the ture difference in performance between the products,...

Applications of Lagrange's method of undetermined mutipliers in physics and economics suggest some analogies between the two disciplinces. By using the work of E. T. Jaynes on information theory, the long standing problem of Maxwell's demon in thermodynamics can be cast as a constrained...