Joined: Dec. 2007
I'm sorry, folks, but I have trouble attending to the minutiae when ED&M are fundamentally wrong in their orientation. From Wikipedia: "Avida is an artificial life software platform to study the evolutionary biology of self-replicating and evolving computer programs (digital organisms)." As I recall, the ability of a virtual organism to reproduce itself depends on how much work it can do, which is determined by its fitness. Different organisms must do different amounts of work to reproduce. Right?
Avida, with the fitness function addressed by ED&M, does not engage in optimization, let alone search. The virtual organisms are operating in a virtual environment offering different payoffs for different behaviors. The population of virtual critters in fact changes to obtain greater payoffs, but this does not mean that the purpose of Avida is optimization. An outcome is not a purpose. More importantly, when a run of Avida does not yield a critter of maximum fitness, the run has not failed. There are still a bunch of "living" virtual organisms, and they always exhibit greater complexity than did the organisms in the initial population.
The objective of the Avida research under consideration was to address emergence of complex features in artificial life. ED&M analyze runs of Avida as though they were runs of an optimizer, and then argue that the ALife simulator is not a good optimizer. This is the kind of abysmal stupidity you get from pretend-scholars who are on a "mission from God" to deliver payback.
I never give them hell. I just tell the truth about them, and they think it's hell. — Harry S Truman