The advent of new families of reconfigurable integrated circuits makes it possible for artificial evolution to manipulate a real physical substrate to produce electronic circuits evaluated in the real world. This raises new issues about the potential nature of electronic circuits, because evolution uses no modelling, abstraction or analysis; only physical behaviour. The simplifying constraints of conventional design methodologies can be dropped, allowing evolution to exploit the full range of physical dynamics available from the silicon medium. This claim is investigated theoretically and in simulation, before presenting the first reported direct evolution of the configuration of a Field Programmable Gate Array (FPGA). Evolution is seen to harness its natural dynamics and exploit them in achieving a real-world task. 1 Introduction There is a type of Very-Large Scale Integrated circuit (a VLSI chip) known as a Field-Programmable Gate Array (FPGA). These chips do not have a predetermin...

. Artificial evolution can operate upon reconfigurable electronic circuits to produce efficient and powerful control systems for autonomous mobile robots. Evolving physical hardware instead of control systems simulated in software results in more than just a raw speed increase: it is possible to exploit the physical properties of the implementation (such as the semiconductor physics of integrated circuits) to obtain control circuits of unprecedented power. The space of these evolvable circuits is far larger than the space of solutions in which a human designer works, because to make design tractable, a more abstract view than that of detailed physics must be adopted. To allow circuits to be designed at this abstract level, constraints are applied to the design that limit how the natural dynamical behaviour of the components is reflected in the overall behaviour of the system. This paper reasons that these constraints can be removed when using artificial evolution, releasing huge potent...

The growth and operation of all living beings are directed by the interpretation, in each of their cells, of a chemical program, the DNA string or genome. This process is the source of inspiration for the Embryonics (embryonic electronics) project, whose final objective is the design of highly robust integrated circuits, endowed with properties usually associated with the living world: self-repair (cicatrization) and self-replication. The Embryonics architecture is based on four hierarchical levels of organization. 1) The basic primitive of our system is the molecule, a multiplexer-based element of a novel programmable circuit. 2) A finite set of molecules makes up a cell, essentially a small processor with an associated memory. 3) A finite set of cells makes up an organism, an application-specific multiprocessor system. 4) The organism can itself replicate, giving rise to a population of identical organisms. We begin by describing in detail the implementation of an artificial cell characterized by

This chapter addresses embodied social interaction inlif6 like agents. Embodiment is discussedf rom both arti cial intelligence and psychology viewpoints. Di#erent degreesof embodiment in biological, virtual and robotic agents are discussed, given the example of a bottomup, behavior-oriented, dynamic control of virtual robots. A `dancing with strangers' experiment shows how the same principles can be applied to physical robot-human interaction. We then discuss the issue of sociality which di#ers in di#erent academic communities with respect to which roles are attributed to genes, memes, and the individual embodied agent.

This paper successively describes the works of Boers & Kuiper, Gruau, Cangelosi et al., Vaario, Dellaert & Beer, and Sims, which all evolve the developmental program of an artificial nervous system. The potentialities of these approaches for automatically devising a control architecture linking the perceptions and the actions of an animat are then discussed, together with their possible contributions to the fundamental issue of assessing the adaptive values of development, learning and evolution.

Self-reproducing, cellular automata-based systems developed to date broadly fall under two categories; the first consists of machines which are capable of performing elaborate tasks, yet are too complex to simulate, while the second consists of extremely simple machines which can be entirely implemented, yet lack any additional functionality aside from self-reproduction. In this paper we present a self-reproducing system which is completely realizable, while capable of executing any desired program, thereby exhibiting universal computation. Our starting point is a simple self-reproducing loop structure onto which we "attach" an executable program (Turing machine) along with its data. The three parts of our system (loop, program, data) are all reproduced, after which the program is run on the given data. The system reported in this paper has been simulated in its entirety; thus, we attain a viable, self-reproducing machine with programmable capabilities. 1 Introduction The study of art...

Some of the major outstanding problems in biology are related to issues of emergence and evolution. These include: (1) how do populations of organisms traverse their adaptive landscapes? (2) what is the relation between adaptedness and fitness? (3) the formation of multi-cellular organisms from basic units or cells. In this paper we study these issues using a model which is both general and simple. The system, derived from the CA (cellular automata) model, consists of a two-dimensional grid of interacting organisms which may evolve over time. We first present designed multi-cellular organisms which display several interesting behaviors including: reproduction, growth, mobility. We then turn our attention to evolution in various environments, including: an environment in which competition for space occurs, an IPD (Iterated Prisoner's Dilemma) environment, an environment of spatial niches, and an environment of temporal niches. One of the advantages of AL models is the opportunities they...

. Cellular automata (CA) are dynamical systems in which space and time are discrete, where each cell obeys the same rule and has a finite number of states. In this paper we study non-uniform CA, i.e. with non-uniform local interaction rules. Our focal point is the issue of universal computation, which has been proven for uniform automata using complicated designs embedded in cellular space. The computation-universal system presented here is simpler than previous ones, and is embedded in the minimal possible two-dimensional cellular space, namely 2-state, 5-neighbor (which is insufficient for universal computation in the uniform model). The space studied is quasi-uniform, meaning that a small number of rules is used (our final design consists of just two rules which is minimal), distributed such that most of the grid contains one rule except for an infinitely small region which contains the others. We maintain that such automata provide us with a simple, general model for studying Artif...

In this article, we try to analyze the requirements of developmental processes from the perspective of their implementation in digital hardware. After recalling the motivations for such an implementation, we concentrate separately on the two mechanisms (cellular division and cellular differentiation) that are exploited by biological systems to realize development. We then describe some of the current and projected solutions to implement such mechanisms in hardware, and conclude by analyzing the most interesting features of developmental approaches. 1

In this paper we shall address the possibility of incorporating a new degree of freedom in the design of electronic systems. It consists of providing the ability to evolve its internal meso-structure while in operation. This new design strategy is allowed by the features included in a new family of FPGA devices, which is called FIPSOC (Field Programmable System On a Chip). Besides a programmable digital section composed of an array of LUT-like configurable cells, the device includes a configurable analog part and a general purpose microcontroller. Furthermore, the configuration scheme used for the programmable digital section allows for an efficient and fast realisation of dynamic reconfiguration principles. As we shall show in this paper, these properties offer two new on-line hardware evolution strategies, giving rise to what we have called virtual meso-structures. 1.