Avida. Design principles Unlike Tierra, Avida assigns every digital organism its own protected region of memory, and executes it with a separate virtual CPU.
By default, other digital organisms cannot access this memory space, neither for reading nor for writing, and cannot execute code that is not in their own memory space. A second major difference is that the virtual CPUs of different organisms can run at different speeds, such that one organism executes, for example, twice as many instructions in the same time interval as another organism. The speed at which a virtual CPU runs is determined by a number of factors, but most importantly, by the tasks that the organism performs: logical computations that the organisms can carry out to reap extra CPU speed as bonus.
Use in research See also References "Testing Darwin", Discover Magazine, February 2005. Breve (software) Breve (sometimes written with lowercase b) is a free, GPL software package that enables users to build 3D simulations of decentralized systems and artificial life.
Users can define the behaviors of multi-agent systems in a 3D world and observe how they interact. Breve includes 3D articulated body physical simulation with collision detection and response and an OpenGL display engine, so one can simulate and visualize semi-realistic creatures and worlds. Critterding. Critterding is an artificial life simulator created by Bob Winckelmans and released as open source under the GPL.
Simulation Critterding is a 3D/Physics based simulator, in which critters try to survive by developing a form of locomotion, find food and reproduce. Critters are made up of two types of body parts which are linked together by joints. The head, coloured red, is where the vision and mouth is located. DigiHive. A simulation of the von Neumann's universal constructor in DigiHive.
Empty circles represent unbound particles while the filled ones represent particles which are part of complexes. The universal constructor (a set of several cooperating programs) joins an information string (the oblique structure) and builds a circle shape structure according to its description encoded by the information string. DigiHive is an abstract environment for artificial life modeling. EcoSim. Evolve 4.0. Evolve 4.0 is an open source, freeware artificial life simulator created by Ken Stauffer.
In its simulated 2D cellular automata, each cell can behave independently as a unicellular organism or potentially as one cell in a multicellular digital organism, growing, moving, eating, reproducing, and eventually even evolving over time. Each cell runs its own program written in a custom programming language called KFORTH (portmanteau of "Ken's Forth"), based on the Forth programming language. Framsticks. Framsticks is a 3D freeware Artificial Life simulator.
Organisms consisting of physical structures ("bodies") and control structures ("brains") evolve over time against a user's predefined fitness landscape (for instance, evolving for speed), or spontaneously coevolve in a complex environment. Noble Ape. Noble Ape is an artificial life development project launched in June, 1996 by Tom Barbalet.
OpenWorm. OpenWorm is an international open science project to simulate the roundworm Caenorhabditis elegans at the cellular level in silico.  Although the long term goal is to model all 959 cells of the C. elegans, the first stage is to model the worm's locomotion by simulating the 302 neurons and 95 muscle cells.
This bottom up simulation is being pursued by the OpenWorm community. So far the physics engine sibernetic has been built and models of the neural connectome and a muscle cell have been created in the NeuroML format. A 3D model of the worm anatomy can be accessed through the web via the OpenWorm browser. The OpenWorm project is also contributing to develop the geppetto simulation framework, a web-based multi-algorithm, multi-scale simulation platform engineered to support the simulation of the whole organism. Background: C. elegans The roundworm C. elegans has one of the simplest brains of any organism, with only 302 neurons. Polyworld. Polyworld Screenshot, 1994 Polyworld is a cross-platform (Linux, Mac OS X) program written by Larry Yaeger to evolve Artificial Intelligence through natural selection and evolutionary algorithms.
Each individual makes decisions based on a neural net using Hebbian learning; the neural net is derived from each individual's genome. The genome does not merely specify the wiring and weighting of the neural nets, but also determines their size, speed, color, mutation rate and a number of other factors. The genome is randomly mutated at a set probability, which are also changed in descendant organisms. TechnoSphere. Part of the fractal landscape of TechnoSphere.
The trees were positioned with a seeding algorithm created by Gordon Selley. Description TechnoSphere was a real-time, 3D simulation of an environment that was populated by virtual creatures. Users across the globe had the capability to create their own creatures through a website. Tierra (computer simulation) According to Thomas S. Ray and others, this may allow for more "open-ended" evolution, in which the dynamics of the feedback between evolutionary and ecological processes can itself change over time (see evolvability), although this claim has not been realized – like other digital evolution systems, it eventually reaches a point where novelty ceases to be created, and the system at large begins either looping or ceases to 'evolve'.
The issue of how true open-ended evolution can be implemented in an artificial system is still an open question in the field of artificial life. Mark Bedau and Norman Packard developed a statistical method of classifying evolutionary systems and in 1997, Bedau et al. applied these statistics to Evita, an Artificial life model similar to Tierra and Avida, but with limited organism interaction and no parasitism, and concluded that Tierra-like systems do not exhibit the open-ended evolutionary signatures of naturally evolving systems. Russell K.
3D Virtual Creature Evolution. 3D Virtual Creature Evolution, abbreviated to 3DVCE, is an artificial evolution simulation program created by Lee Graham. The website is currently down. Its purpose is to visualize and research common themes in body plans and strategies to achieve a fitness function of the artificial organisms generated and maintained by the system in their given environment. The program was inspired by Dr. Karl Sims’s artificial evolution program, Evolved Virtual Creatures, in 1994. The program is run through volunteers who download the program from the home website and return information from completed simulations. It is currently only available on Windows and in some cases Linux. Settings 3DVCE uses evolutionary algorithms to simulate evolution. Fitness function is then determined.
Module-based. Neural-net based. Parameter-based.