Avida
Encyclopedia
Avida is an artificial life
Artificial life
Artificial life is a field of study and an associated art form which examine systems related to life, its processes, and its evolution through simulations using computer models, robotics, and biochemistry. The discipline was named by Christopher Langton, an American computer scientist, in 1986...

 software platform to study the evolutionary biology of self-replicating and evolving computer programs (digital organism
Digital organism
A digital organism is a self-replicating computer program that mutates and evolves. Digital organisms are used as a tool to study the dynamics of Darwinian evolution, and to test or verify specific hypotheses or mathematical models of evolution...

s). Avida is under active development by Charles Ofria
Charles Ofria
Dr. Charles A. Ofria is currently an Associate Professor in the Department of Computer Science and Engineering, the director of the Digital Evolution Lab at Michigan State University and a co-founder of the BEACON Center for the Study of Evolution in Action. Ofria's research focuses on the...

's Digital Evolution Lab at Michigan State University
Michigan State University
Michigan State University is a public research university in East Lansing, Michigan, USA. Founded in 1855, it was the pioneer land-grant institution and served as a model for future land-grant colleges in the United States under the 1862 Morrill Act.MSU pioneered the studies of packaging,...

 and was originally designed by Ofria, Chris Adami
Chris Adami
Christoph Carl Herbert Adami is a professor at Michigan State University. He is best known for his work on Avida, an artificial life simulator used to study evolutionary biology. He received the NASA Exceptional Achievement Medal while serving at JPL...

 and C. Titus Brown at Caltech in 1993. The software was inspired by the Tierra
Tierra (computer simulation)
Tierra is a computer simulation developed by ecologist Thomas S. Ray in the early 1990s in which computer programs compete for central processing unit time and access to main memory...

 system.

Design principles

Tierra simulated an evolutionary system by introducing computer programs that competed for computer resources, specifically processor (CPU) time and access to main memory. In this respect it is similar to core wars, but differs in that the programs being run in the simulation are able to modify themselves, and thereby evolve. Tierra's programs are artificial life organisms.

In Avida, every digital organism lives in its own protected region of memory, and is executed by its own virtual CPU
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...

. 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. Whereas in Tierra the organisms effectively share and compete for one "brain", in Avida each one has its own brain.

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: Tasks are logical computations that the organisms can carry out to reap extra CPU speed as bonus.

Use in research

Adami and Ofria, in collaboration with others, have used Avida to conduct research in digital evolution, and the scientific journals Nature
Nature (journal)
Nature, first published on 4 November 1869, is ranked the world's most cited interdisciplinary scientific journal by the Science Edition of the 2010 Journal Citation Reports...

and Science
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....

have published four of their papers. Nature published "The Evolutionary Origin of Complex Features" in 2003, in which the evolution of a mathematical equals operation
Operator (programming)
Programming languages typically support a set of operators: operations which differ from the language's functions in calling syntax and/or argument passing mode. Common examples that differ by syntax are mathematical arithmetic operations, e.g...

is constructed of at least 19 simpler, precisely ordered instructions.

See also

  • Artificial life
    Artificial life
    Artificial life is a field of study and an associated art form which examine systems related to life, its processes, and its evolution through simulations using computer models, robotics, and biochemistry. The discipline was named by Christopher Langton, an American computer scientist, in 1986...

  • Digital organism
    Digital organism
    A digital organism is a self-replicating computer program that mutates and evolves. Digital organisms are used as a tool to study the dynamics of Darwinian evolution, and to test or verify specific hypotheses or mathematical models of evolution...

  • Digital organism simulators
  • Breve
    Breve (software)
    Breve is a free, GPL software package that enables users to build 3D simulations of decentralized systems and artificial life...

     (actually a multi-purpose simulation environment)
  • Darwinbots
    Darwinbots
    DarwinBots is an open source artificial life simulator, originally developed by Carlo Comis, providing a virtual environment in which a number of digital organisms called "bots" interact, fight for resources, and eventually reproduce and evolve.-Simulation:...

  • Tierra
    Tierra (computer simulation)
    Tierra is a computer simulation developed by ecologist Thomas S. Ray in the early 1990s in which computer programs compete for central processing unit time and access to main memory...

  • Nanopond
  • Evolve 4.0
    Evolve 4.0
    Evolve 4.0 is an open source, freeware Artificial life simulator by Ken Stauffer. In its simulated 2D cellular automata, each cell can behave independently as unicellular organism or potentially as cells in a multicellular Digital organisms, growing, moving, eating, reproducing, and eventually...

  • Conway's Game of Life
    Conway's Game of Life
    The Game of Life, also known simply as Life, is a cellular automaton devised by the British mathematician John Horton Conway in 1970....


  • External links


    Scientific publications featuring Avida

    • C. Adami and C.T. Brown (1994), Evolutionary Learning in the 2D Artificial Life Systems Avida, in: R. Brooks, P. Maes (Eds.), Proc. Artificial Life IV, MIT Press, Cambridge, MA, p. 377-381. arXiv:adap-org/9405003v1
    • R. E. Lenski, C. Ofria, T. C. Collier, C. Adami (1999). Genome Complexity, Robustness, and Genetic Interactions in Digital Organisms. Nature 400:661-664. abstract of this article
    • C.O. Wilke, J.L. Wang, C. Ofria, R.E. Lenski, and C. Adami (2001). Evolution of Digital Organisms at High Mutation Rate Leads To Survival of the Flattest. Nature 412:331-333.
    • R.E. Lenski, C. Ofria, R.T. Pennock, and C. Adami (2003). The Evolutionary Origin of Complex Features. Nature 423:139-145.
    • S.S. Chow, C.O. Wilke, C. Ofria, R.E. Lenski, and C. Adami (2004). Adaptive Radiation from Resource Competition in Digital Organisms. Science 305:84-86.
    • J. Clune, D. Misevic, C. Ofria, R.E. Lenski, S.F. Elena, and R. Sanjuán. Natural selection fails to optimize mutation rates for long-term adaptation on rugged fitness landscapes. PLoS Computational Biology 4(9): 2008. full text available
    • Clune J, Goldsby HJ, Ofria C, and Pennock RT (2011) Selective pressures for accurate altruism targeting: Evidence from digital evolution for difficult-to-test aspects of inclusive fitness theory. Proceedings of the Royal Society. pdf
    • Benjamin E. Beckmann, Philip K. McKinley, Charles Ofria (2007). Evolution of an adaptive sleep response in digital organisms. ECAL 2007 pdf
    The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
     
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