This paper gives details of Squirm3, a new artificial environment based on a simple physics and chemistry that supports self-replicating molecules somewhat similar to DNA.The self-replicators emerge spontaneously from a random soup given the right conditions.Interactions between the replicators can result in mutated versions that can out-perform their parents.We show how artificial chemistries such as this one can be implemented as a cellular automaton.We concur with [9] that artificial chemistries are a good medium in which to study early evolution.

We succeeded for the first time in constructing evolutionary systems on a simple 9-state 5-neighbor cellular automata (CA) space by utilizing Langton's self-reproducing loop. CA are deterministic dynamical systems capable of representing extremely complex nonlinear phenomena, where time, space and states of sites are all discrete. Many CA models of self-reproductive behavior of theoretical organisms have so far been energetically studied, but the evolutionary process of organisms driven by variation and natural selection has never been realized on CA space yet. In this dissertation, we added three improvements into Langton's loop, i.e., to realize a kind of death by introducing a new dissolving state `8' into the set of states of the CA, to enhance the adaptability (a degree of the variety of situations in which the structures in the CA space can operate regularly) of the selfreproductive mechanism described by the state-transition rules of the CA, and to modify the initial structure o...

A new self-replicating cellular automata (CA) model is proposed as a latest effort toward the realization of an artificial evolutionary system on CA where structural complexity of self-replicators can increase in some cases. I utilize the idea of `shape encoding' proposed by Morita and Imai (Morita & Imai 1996b) and make the state-transition rules of the model allow organisms to transmit genetic information to others when colliding against each other. Simulations with random initial configuration demonstrate that it is possible that the average length of organisms and the average frequency of brancing per organism both increase, with decreasing self-replication fidelity, and saturate at some constant level. The saturation is caused in part by the fixation of place and shape of organisms onto particular sites. This implies the necessity of introducing some fluidity of site arrangements into the model for further development of evolutionary models using CA-like artificial medi...

This paper provides a glimpse into the questions that arise and some of their possible answers. We set out by describing the implementation of selfreplication and evolution processes in artificial media. Then, we go on to observe that while these two conditions may be

In this paper, we present a possible implementation of arithmetic functions (notably, addition and multiplication) using self-replicating cellular automata. The operations are performed by storing a dedicated program (sequence of states) on self-replicating loops, and letting the loops retrieve the operands, exchange data among themselves, and perform the calculations according to a set of rules. To determine the rules required for addition and multiplication, we exploited an existing algorithm for computation in the cellular automata environment and adapted it to exploit the features of self-replicating loops. This approach allowed us to study a variety of issues (synchronization, data exchange, etc.) related to the use of self-replicating machines for complex operations.

The study of self-replicating structures in Computer Science has been taking place for more than half a century, motivated by the desire to understand the fundamental principles and algorithms involved in self-replication. The bulk of the literature explores self-replicating forms in Cellular Automata. Though trivially self-replicating programs have been written for dozens of languages, very little work exists that explores self-replicating forms in programming languages. This paper reports initial investigations into selfreplicating expressions in the Lambda Calculus, the basis for functional programming languages. Mimicking results from the work on Cellular Automata, selfreplicating Lambda Calculus expressions that also allow the application of an arbitrary program to arbitrary data are presented. Standard normal order reduction, however, will not reduce the sub-expression representing the program application. Two approaches of dealing with this, hybrid reduction and parallel reduction, are discussed, and have been implemented in an interpreter.

In the early 1950s, John von Neumann designed a cellular automaton implementing a universal self-replicating structure. More than 40 years after his death, the first hardware implementation of von Neumann's transition rule is presented. Unfortunately, this implementation only allows small systems to be realized, and not the complete structure, which would require 100 000--200 000 cells, according to some estimations. A logic circuit which implements the transition rule and represents a single cell of the array has been developed. The applications of this implementation lie mainly in the pedagogical domain. It can be used as a demonstration tool for courses on cellular automata.

This paper introduces a method through which, using genetic algorithms on two dimensional cellular automata, we obtain emergent phenomena of self-replication. Three

Creating algorithmic approach for generating self-replicate patterns of digital images is important and difficult task. Researchers face with many challenges in developing tiling algorithms such as providing simple and applicable algorithm to describe complex patterns. This paper used cellular automata with extended moor neighborhood to generate self replicate patterns of digital images. Growth from simple motif in two dimensional cellular automata can produce self replicate patterns with complicated boundaries, characterized by a variety of growth dimensions. The proposed approach leads to accurate and scalable algorithm for generating patterns. The results of implemented algorithm demonstrate our approach with a variety of patterns.

© 2006 Caudle; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License