Size distributions in some ecosystems follow a power (Zipf-) law behavior spanning up to two ten decades. A model for the origins of this scaling behavior is presented. The model shows that the intrinsic dynamics of the system leads to a power law distribution, , with , in agreement with field...

Economics have long associated decision making wit optimization. The decision maker chooses an action from a known choice set C. he chosen action maximizes a known real-valued objective function F (.): C -- R. Optimization assumes enough knowledge of C and f(.) to determine an optimal action....

The field of Psychology, which is the study of the mind, is one of extraordinary breadth. As a field of study, Psychology must encompass not only a description of the many and various aspects of everything minds do, but of increasing interest in the 20th Century, the mechanisms by which specific...

Most models of natural selection assume either that the material environment remains constant or that it fluctuates in ways unrelated to changes in gene frequencies (and therefore changes in the distribution of phenotypes) of the organism undergoing selection. In this paper, we consider what...

Moments after a baseball batter has hit a fly ball, an outfielder has to decide whether to run forward or backward to catch the ball. Judging a fly ball is a difficult task, especially when the fielder is in the plane of the ball's trajectory. There exists several alternative hypotheses in the...

According to the Darwinian theory of evolution, adaptation results from spontaneously generated genetic variation and natural selection. Mathematical models of this process can be seen as describing a dynamics on an algebraic structure which in turn is defined by the processes which generate...

Recent work has demonstrated that many social networks, and indeed many networks of other types also, have broad distributions of vertex degree. Here we show that this has a substantial impact on the shape of ego-centered networks, i.e., sets of network vertices that are within a given distance...

The heights of energy barriers separating two (macro-)states are useful for estimating transition frequencies. In non-degenerate landscapes the decomposition of a landscape into basins surrounding local minima connected by saddle points is straightforward and yields a useful definition of...

How does one optimize a fitness function when the values it generates have a stochastic component? How does one simultaneously optimize multiple fitness criteria? These questions are important for many applications of evolutionary computation in an experimental environment. Solutions to these...