|Wesley R. Elsberry
Joined: May 2002
While I did stress that the genomic content of the initial organism, and thus the Avidian population, could only acquire the new instructions via mutation, once an ancestral organism had one or more of those, they would be passed down to offspring with the usual frequency. And any effects they had on the organism could yield a difference in fitness, driving the usual selective processes. I think saying mutation was the only operative process goes too far. Not including the instructions in any way in the initial organism simply eliminates the possibility that I as experimenter set up a particular outcome by whatever arrangement of movement-relevant instructions might be set in that initial organism.
One question I was asked at SSCI in 2009 was why use Avida and not something like Echo. And while the efficient answer is that when one is at the Devolab, one is usually going to be using Avida, I did survey the available software at the time for applicability to the question I was looking at. The software systems allowing for agent movement all treated movement as a primitive property, often requiring some fixed movement strategy be defined for the agents a priori. I was interested in looking at what evolution could do given just the sort of capabilities underlying movement as seen in organisms like E. coli, but without specifying how those capabilities were used. And that kind of question was not what the other software packages could address.
"You can't teach an old dogma new tricks." - Dorothy Parker