By grouping several sites together into one, a cellular automaton can be transformed into another with more states and a smaller neighborhood; if the neighborhood has just two sites, we can think of the resulting CA rule as a binary operation. We show that if the blocked rule satisfies an...

We jointly address two puzzles, namely what accounts for the evolutionary success of both: (a) individually costly and group-beneficial forms of human sociality towards non-kin; and (b) those group-level institutional structures such as food sharing and monogamy which have emerged and diffused...

We study some simple models of disease transmission on small-world networks, in which either the probability of infection by a disease or the probability of its transmission is varied, or both. The resulting models display epidemic behavior when the infection or transmission probability rises...

In many cases fitness landscapes are obtained as particular instances of random fields by assigning a large number of random parameters. Models of this type are often characterized reasonably well by their covariance matrices. We characterize isotropic random fields on finite graphs in terms of...

We construct stationary Markov equilibria for an economy with fiat money, one nondurable commodity, countably-many time periods, and a continuum of agents. The total production of commodity remains constant, but individual agents' endowments fluctuate in a random fashion from period to period....

Recent developments in the study of the pehistory of the northern Mogollon and Anasazi areas of the North American Southwest are reviewed, with emphasis on the pre-A.D. 1150 period, in an attempt to identify key empirical results and incipient interpretive directions.

The capacity of a model immune network in terms of the number of different antigens that can be vaccinated against without any memory lost is computed and tested by numerical simulations. We also investigate memory loss and failure to vaccinate due to overcrowing the network with too may...

We study analytically the steady-state regime of a network of n error-prone self-replicating templates forming an asymmetric hypercycle and its error tail. We show that the existence of a master template with a higher non-catalyzed self-replicative productivity, a, than the error tail ensures...

In this paper we rigorously formulate the Schema Theorem for Genetic Programming (GP). This involves defining a schema, schema order, and defining length and accounting for the variable length and the non-homologous nature of GP'S representation. The GP Schema Theorem and the related notion of a...