tech. rep. available on evolving trail-following organisms

[Dr Michael G Dyer]

Evolution as a Theme in Artificial Life:  The Genesys/Tracker System* 

David Jefferson, Robert Collins, Claus Cooper
Michael Dyer, Margot Flowers, Richard Korf
Charles Taylor, Alan Wang

Abstract

Direct, fine-grained simulation is a promising way of investigating 
and modeling natural evolution.  In this paper we show how we can 
model a population of organisms as a population of computer programs, 
and how the evolutionarily significant activities of organisms 
(birth, interaction with the environment, migration, sexual 
reproduction with genetic mutation and recombination, and death) can 
all be represented by corresponding operations on programs.  We 
illustrate these ideas in a system built for the Connection Machine 
called Genesys/Tracker, in which artificial "ants" evolve the ability 
to perform a complex task.  In less than 100 generations a population 
of 64K "random" ants, represented either as finite state automata or 
as artificial neural nets, evolve the ability to traverse a winding 
broken "trail" in a rectilinear grid environment.  Throughout this 
study we pay special attention to methodological issues, such as the 
avoidance of representational artifacts, and to biological 
verisimilitude.

* To appear in J. D. Farmer, C. Langton, S. Rasmussen and C. Taylor (Eds.), 
Artificial Life II, Addison-Wesley, in press.

For a copy of this tech. rep., please send e-mail 
to:      valerie at cs.ucla.edu
requesting  "Jefferson et al. -- Evolution as Theme in ALife"
Be sure to include your USA mail address.