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djmullen



Posts: 327
Joined: Jan. 2006

(Permalink) Posted: July 11 2006,20:53   

HUMOR ALERT!!  Salvador's on an Avida roll again!

Salvador Cordoba, the man who makes Dembski look like an intellectual, is hanging himself out to dry once more.  In the Uncommon Dullards thread, "Tautologies and Theatrics (part 1): adventures in Avida", Salvador promises to shoot himself in the foot yet again by doing a three part series on the artifical life program, "Avida".

I urge everybody who appreciates the humor that is inherant in ID to read all three parts of this thread closely because every time Salvador starts talking about Avida, the results are invariably hilarious.  It has been this way since the first time he tangled with this program, back in the summer of 2004.

Avida is a program in which 'digital life forms', which are short programs written in a simple computer language, are run by the Avida program.  The person running the program can set various conditions, such as several types of mutations, that will change the code and reward it if it becomes more efficient.

Hearing about this program, Salvador procured a copy, (it's open source) installed it, selected a value for random point mutations that gave each instruction a .5 chance of being mutated every time the organism divided, started it running and then triumphantly reported that he had found a serious flaw in Avida - the digital organisms grew in an environment of lethal digital 'radiation' that should have fried every organism the first time it tried to reproduce.

He and RBH went around and around and around some more on this, with the argument being greatly hampered by the fact that RBH understands Avida and Salvador doesn't.  RBH finally sent Salvador's inputs and outputs to the Avida group and graduate student Evan Dorn responded here.

It turns out that what was going on was exactly what anybody who had even a sketchy knowledge of Avida would have predicted: every single organism was dead!  They had all been blasted to smithereens the first time they tried to reproduce as approximately one half of their instructions were mutated!  This was all pretty clear to RBH and anybody else familiar with Avida, but not, of course, to Salvador who's more of a doer kind of guy rather than an understander.  (Much like the current administration.)

Sal also made a second blunder: while fooling around with point mutation values, he set the probability of a mutation to 50,000.  This created a rather severe problem, since the highest probability you can have in the real world is 1.  It turns out that when Avida encountered a probability 50,000 times higher than the maximum possible, it responded by shutting off point mutations altogether and Sal's digital organisms thus reproduced unimpeded.

Sal still hasn't realized either blunder.  As he puts it, "...Avidian creatures have some features which seriously decouple them from reality. The proof was right there, because even after this bug [the .5 probability of mutation in each instruction] was fixed, the make-believe creatures could still be made to breed in high radiation environments (not quite like rabbits, but still enough to draw notice). The bug fix only slowed down reproduction in high radiation environments, it didn’t stop it. In fact the creatures (being immortal) would oscillate between sterility and fertility as long as one kept bombarding them with radiation! Doesn’t that strike you all as a bit odd?"  (Emphasis in the original.)

Well, not actually, but perhaps that's because I read Evan Dorn's reply to Salvador, which is cited above:  "Mr. Cordova claims to have observed inconsistent behavior in Avida which he believes disproves its' validity as an experimental platform. Upon examination, it is clear that he is simply misunderstanding the output of his experiments, and that at high (but valid) mutation probabilities, Avida is behaving exactly as expected - all organisms are dead."  

He goes on to say, "Explanation: Put simply, the population was dead. What Mr. Cordoba observed was slow, random activity of non- replicating random strings.

Whether or not the strings of instructions existing in grid cells genotypes are valid, replicating organisms, Avida will dutifully execute their instructions. In this case, the ancestor organism was thoroughly randomized in the first update, as would be expected at Pmut=0.5. However, the execution of random computer instructions will occasionally include the execution of the "allocate" instruction, creating new room at the end of the "genome" if other instructions happen to have put a non-zero number in the appropriate register. Also, the occasional "divide" will execute when other instructions have loaded integer values into the appropriate register ... meaning some piece of the randomized genome will get split into another grid cell. Without the actual code for organized replication, this will occur very slowly and all of these divides will contain random-length groups of random instructions. While yes, this process will slowly fill the grid cells, it is in no way analogous to life: nothing is replicated with fidelity, and no information is conserved.

Conclusion: Mr. Cordova has experimentally demonstrated that there is in no mechanism protecting genomes from randomization by killing the ancestor organism with a high mutation rate and observing the "brownian motion" activity of dead, random, sequences of computer instructions."

In other words, Salvador thoroughly skrootched the digital organisms with his torrent of point mutations, but Avida has no way of knowing this and keeps executing each individual instruction in the defunct 'organism'.  Once in a while it finds and executes an 'allocate' instruction which adds empty memory to the space the dead organisms live in.  Once in a while it also finds and executes a 'divide' command, which splits off another cell (full of randomized instructions that were once a digital organism) and a new 'life form' is born - at least it looks that way if you don't know what the he11 you're talking about.

Has Salvador figured this out?  Of course not, he's an IDist and figuring things out is against his personal moral code.  Is this ignorance going to stop him from making a further fool of himself?  Of course not, he's an IDist and God wants him to make a fool of himself as a warning to others and to provide good clean entertainment to ID critics.

Personally, I'm going get some popcorn and sit back and enjoy this one.

  
  29999 replies since Jan. 16 2006,11:43 < Next Oldest | Next Newest >  

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