Avida is the most richly developed Tierra-derivative system. It has its own web page, so please go there for more information.
Physis is a general framework for Tierra and Avida-like systems. It supports several virtual machine architectures and different instruction sets.
Here is a German site with some information on Tierra.
Pargellis, A. N. 1996. The spontaneous generation of digital "life". Physica D. 91:86-96.
Pargellis, A. N. 1996. The evolution of self-replicating computer organisms. Physica D. 98:111-127.
Helix4 is a Tierra-like system written by Ed T. Toton in March of 1993, one of the more notable differences being that it has a larger (and perhaps more fragile) instruction set. It even has some limited genebanking functions. http://www.necrobones.com/alife/
============================================================= _ = Ed T. Toton III, Wanderer -===- NecroBones@necrobones.com = ( ) ======[Phoenix, Lurker]--=======--[ BONES Dragon (UDIC) ]==== --+-- == NecroBones Enterprises -===- http://www.necrobones.com/ == | ============================================================= |
Yedid, Gabriel, Graham Bell, and Rosemarie Swanson. A system of evolving self-replicators shows unexpected population dynamics and patterns of genotypic succession. unpublished, contact: email@example.com
Barton-Davis, Paul. Unpublished. Independent implementation of the Tierra system, contact: firstname.lastname@example.org.
Brooks, Rodney. Unpublished. Brooks has created his own Tierra-like system, which he calls Sierra. In his implementation, each machine instruction consists of an opcode and an operand. Successive instructions overlap, such that the operand of one instruction is interpreted as the opcode of the next instruction. Contact: email@example.com
Kampis, George. 1993. Life-like computing beyond the machine metaphor. In: [R. Paton ed] Computing with biological metaphors. Chapman and Hall, London.
Davidge, Robert. 1995. Computer processors which behave like unicellular organisms: a thesis in artificial life. Ph. D. Thesis. The University of Sussex.
Davidge, Robert. 1993. Looping as a means to survival: playing Russian roulette in a harsh environment. In: Self organization and life: from simple rules to global complexity, proceedings of the second European conference on artificial life. Contact: firstname.lastname@example.org
Davidge, Robert. 1992. Processors as organisms. CSRP 250. School of Cognitive and Computing Sciences, University of Sussex. Presented at the ALife III conference. Contact: email@example.com
de Groot, Marc. Unpublished. Primordial soup, a Tierra-like system that has the additional ability to spawn self-reproducing organisms from a sterile soup. Contact: firstname.lastname@example.org, email@example.com, firstname.lastname@example.org
Gray, James. Unpublished. Natural selection of computer programs. An early Tierra-like system, but evolving real programs on a real rather than a virtual machine, and predating Tierra itself: ``I have attempted to develop ways to get computer programs to function like biological systems subject to natural selection.... I don't think my systems are models in the usual sense. The programs have really competed for resources, reproduced, run, and `died'. The resources consisted primarily of access to the CPU and partition space.... On a PDP11 I could have a population of programs running simultaneously.'' Contact: Gray.James_Lemail@example.com
Litherland, J. 1993. Open-ended evolution in a computerised ecosystem. A Masters of Science dissertation in the Department of Computer Science, Brunel University, England. Contact: firstname.lastname@example.org
Maley, Carlo C. 1993. A model of early evolution in two dimensions. Masters of Science thesis, Zoology, New College, Oxford University. Contact: email@example.com
Rich, Roger. 1993. Artificial life universe containing heterosexual reproduction and communication. Contact: Roger Rich, Rocinante Technologies, 417 N Quentin, Wichita, KS 67208. Tel: 316-652-0794, Fax: 316-636-4780. Wichita.ncr.com!Roger.Rich
Rich, Roger. 1993. Phoneme 1.0 - User's Guide.
Swanson, Rosemarie. 1993. Sequence analyses of Tierran evolution. Contact: Rosemarie Swanson, Department of Biochemistry/Biophysics, Texas A&M University, College Station, TX 77843-2128. firstname.lastname@example.org
Putnam, Jeffrey B. date? Experiments in non-Tierra artificial life. Contact: Jeffrey B Putnam, New Mexico Institute of Mining and Technology, Socorro, NM 87801. email@example.com
Manousek, Wolfgang. 1992. Spontane Komplexitaetsentstehung --- TIERRA, ein Simulator fuer biologische Evolotion. Diplomarbeit, Universitaet Bonn, Germany, Oktober 1992. Contact: Kurt Stueber, firstname.lastname@example.org
Skipper, Jakob. 1992. The computer zoo -- evolution in a box. In: Francisco J. Varela and Paul Bourgine [eds.], Toward a practice of autonomous systems, proceedings of the first European conference on Artificial Life. MIT Press, Cambridge, MA. Pp. 355-364. Contact: Jakob.Skipper@copenhagen.ncr.com
Surkan, Al. Unpublished. Self-balancing of dynamic population sectors that consume energy. Department of computer science, UNL. ``Tierra-like systems are being explored for their potential applications in solving the problem of predicting the dynamics of consumption of a single energy carrying natural resource''. Contact: email@example.com
Tackett, Walter, and Jean-Luc Gaudiot. 1993. Adaptation of self-replicating digital organisms. Proceedings of the International Joint Conference on Neural Networks, Nov. 1993, Beijing, China. IEEE Press. Contact: firstname.lastname@example.org, email@example.com
Rasmussen, Steen, Carsten Knudsen, Rasmus Feldberg, and Morten Hindsholm. 1990. The coreworld: emergence and evolution of cooperative structures in a computational chemistry. Physica D 42: 111-134.
Rasmussen, S., C. Knudsen, and R. Feldberg. 1991. Dynamics of programmable matter. In: Langton, C., C. Taylor, J. D. Farmer, & S. Rasmussen [eds], Artificial Life II, Santa Fe Institute Studies in the Sciences of Complexity, vol. X, 211-254. Redwood City, CA: Addison-Wesley.
Tim Taylor. March 1997. Studying Evolution with Self-Replicating Computer Programs. Contact: Tim Taylor, Department of Artificial Intelligence, University of Edinburgh, 5 Forrest Hill, Edinburgh EH1 2QL, Scotland, U.K., firstname.lastname@example.org
Tim Taylor. June 1996. The COSMOS environment and REPLiCa programming language.
Florent de Dinechin. March 1997. Ziemia: a Bidimensional Tierra-like System. Contact: Florent de Dinechin, IRISA, campus de Beaulieu, Rennes, France, email@example.com
Hideaki Suzuki. 1996. Functional emergence with multiple von Neumann computers. Artificial Life V Conference Proceedings, p. 89-96. Contact: Hideaki Suzuki, Elemental Research Lab. 14, Honda R&D Co., Ltd. Wako Research Center, 1-4-1 Chuo, Wako-shi, Saitama 351-01, Japan, firstname.lastname@example.org
Hideaki Suzuki. 1996. Drastic evolution induced by genetic recombination. Contact: Hideaki Suzuki, Elemental Research Lab. 14, Honda R&D Co., Ltd. Wako Research Center, 1-4-1 Chuo, Wako-shi, Saitama 351-01, Japan, email@example.com
I've just made CoreLife available, a very fast MS-DOS program I wrote a while ago which can run Tierran code according to your original specifications (a 64K core memory, no networking ) You can download it from my homepages at:
It was written mainly in PC assembly language for speed, and is reasonably close to the specs from some of your earlier papers, but was written completely independently from your Tierra program sources, since I did not have access to those when I wrote CoreLife.
This will be evident from the difference in user interface and approach (speed and interactivity, no recording of creatures' family tree data) but I hope you'll find it useful anyway. For example, it has a (primitive) graphical user interface where you can do fun stuff like 'spray' mutations on live creatures and watch the population recover and diversify. There's also context-sensitive help by pressing F1.
Regards, Erik de Neve firstname.lastname@example.org
Freelance programmer and devoted Tierra / a-life enthusiast
Evolution Software http://www.xs4all.nl/~alif
Official Consultant for Epic MegaGames http://www.epicgames.co
Alvy Ray Smith lent me the reprints below. These are very well developed evolutionary systems, and the papers show well developed Artificial Life thinking, in the period of 1962 - 1967. The work is also discussed in the book Darwin Among the Machines by George Dyson. These are really worth reading:
Nils Aall Barricelli. 1962. Numerical testing of evolution theories. Part I. Theoretical introduction and basic tests. Acta Biotheoretica Vol. XVI, Pars I/II: 69-98.
Nils Aall Barricelli. 1963. Numerical testing of evolution theories. Part II. Preliminary tests of performance. Symbiogenesis and Terrestrial life. Acta Biotheoretica Vol. XVI, Pars III/IV: 99-126.
Jon Reed, Robert Toombs and Nils Aall Barricelli. 1967. Simulation of self-reproducing numeric patterns by data processing machines, effects of hereditary control, mutation type and crossing. Journal of Theoretical Biology 17: 319-342.