Third European Conference on Artificial Life Granada, Spain, June 4–6, 1995 Proceedings
Artificial life is extending the scope of molecular evolutionary biology as it tries to complement natural life on earth by searching for systems with properties that are sufficient to allow for evolution. Evolution is characterized by specific forms of dynamics that are based on the capability of replication. RNA molecules form a toy universe calles the RNA world that shares many features with current...
Foundational controversies in artificial life and artificial intelligence arise from lack of decidable criteria for defining the epistemic cuts that separate knowledge of reality from reality itself, e.g., description from construction, simulation from realization, mind from brain. Selective evolution began with a description-construction cut, i.e., the genetically coded synthesis of proteins. The...
This paper is concerned with foundations of ALife and its methodology. A brief look into the research program of ALife serves to clarify its goals, methods and subfields. It is argued that the field of animat research within ALife follows a program which is considerably different from the rest of ALife endeavours. The simulation — non-simulation debate in behavior-based robotics is revisited in the...
Is there an Edge of Chaos, and if so, can evolution take us to it? Many issues have to be settled before any definitive answer can be given. For quantitative work, we need a good measure of complexity. We suggest that convergence time is an appropriate and useful measure. In the case of cellular automata, one of the advantages of the convergence-time measure is that it can be analytically approximated...
In this paper, I propose a neo-Heideggerian framework for A-Life. Following an explanation of some key Heideggerian ideas, I endorse the view that persistent problems in orthodox cognitive science result from a commitment to a Cartesian subject-object divide. Heidegger rejects the primacy of the subject-object dichotomy; and I set about the task of showing how, by adopting a Heideggerian view, A-Life...
The lack within AL of an agreed-upon notion of life and of a set of criteria for identifying life is considered. I propound a reflection upon the codified nature of the organization of living beings. The necessity of a guiding notion based on the coding is defended. After sketching some properties of the genetic code I proceed to consider the issue of functionalism as strategy for AL. Several distinctions...
Biology is, better than anything else, about existence in time. Hence biological reality cannot be defined without reference to a temporally situated observer. The coupled or detached character of this observer (with respect to the own time variable of the system) provides a link between the observer and the observed. This connections delimits the kinds of scientific descriptions that can be given...
Although the origin of self-sustaining, autoreplicating systems capable of undergoing Darwinian evolution is still unknown, a research program based on the hypothesis of chemical and precellular evolution has provided a framework within which the abiotic synthesis of biochemical monomers and membrane components, the experimental study of replicative systems, and the interactions between different...
Recently a model formed by self-replicative units with catalytic capabilities evolving in an extended system has been presented. It has been shown that under particular conditions this model exhibits spatial compartimentation without any kind of membrane. In the framework of ALife, we suggest that this model can allow a global growth in the complexity of those models based on the hypothesis of the...
We view the folding of RNA-sequences as a map that assigns a pattern of base pairings to each sequence, known as secondary structure. These preimages can be constructed as random graphs (i.e. the neutral networks associated to the structure s). By interpreting the secondary structure as biological information we can formulate the so called Error Threshold of Shapes as an extension of Eigen's...
A theory for evolution of molecular sequences must take into account that a population consists of a finite number of individuals with related sequences. Such a population will not behave in the deterministic way expected for an infinite population, nor will it behave as in adaptive walk models, where the whole of the population is represented by a single sequence. Here we study a model for evolution...
Replicators don't. Replicate, that is. This is the shocking conclusion to which I have been forced by my attempt to figure out what precisely Richard Dawkins means by the term “replicator”. Actually, it seems that Dawkins uses the term in at least two fundamentally different ways; but according to Dawkins' own specification of the problem which the “replicator” concept was intended to solve (namely,...
RNA viruses can be an adequate bridge between life and artificial life. Under experimental conditions the parameters that in last instance are responsible for the evolution of replicons resembling primitive life forms can be easily studied. One year of a RNA virus evolving may be equivalent to one million years of an evolving DNA-based entity. High mutation rates as well as very short life cycles...
The structural biocomplexity of two viral structures is evaluated: that of the small RNA tobacco mosaic virus (TMV) and that of the larger dsDNA bacteriophage T4. Tobacco mosaic virus was chosen as a paradigm of a self-organizing biostructure, while the T4 represents biostructures where genome directed instructions are essential for the achievement of the correct virion structure. A large difference...
A new model, “Tile Automaton” (“Tile” for short)is proposed for the evolution of metabolism, where the importance of dynamical many-body relationships and spatial effects of shapes are stressed. Like the computer game “Tetris”, our automaton consists of tiles with a variety of sizes, and shapes, moving in a 2-dimensional space with some velocity coded by a real number. By the collision, tiles react...
Co-evolution can give rise to the “Red Queen effect”, where interacting populations alter each other's fitness landscapes. The Red Queen effect significantly complicates any measurement of co-evolutionary progress, introducing fitness ambiguities where improvements in performance of co-evolved individuals can appear as a decline or stasis in the usual measures of evolutionary progress. Unfortunately,...
In order to better understand life, it is helpful to look beyond the envelop of life as we know it. A simple model of coevolution was implemented with the addition of genes for longevity and mutation rate in the individuals. This made it possible for a lineage to evolve to be immortal. It also allowed the evolution of no mutation or extremely high mutation rates. The model shows that when the individuals...
A problem of self-referential paradox and self-reproduction is discussed in a network model of machines and tapes. A tape consists of a bit string, encoding function of a machine. Tapes are replicated when it is attached by an adequate machine. Generally, a tape is replicated but it may be different from the original one. In this paper, external noise evolves diversity in a system. New reaction pathway...
In the field of optimization and machine learning techniques, some very efficient and promising tools like Genetic Algorithms (GAs) and Hill-Climbing have been designed. In this same field, the Evolving Non-Determinism (END) model presented in this paper proposes an inventive way to explore the space of states that, using the simulated “incremental” co-evolution of some organisms, remedies some drawbacks...
This paper investigates the dynamics of co-evolution of various types of animats. For this purpose, we use a problem we call the Blind Hunger Dilemma. This problem investigates the emergence of collective behavior concerned with shared resource. Our model of co-evolution is inspired by Margulis's idea of parasitism and symbiosis which she applies to the origin of the current eukaryotic cell. Originally,...