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  Topic: Uncommonly Dense Thread 2, general discussion of Dembski's site< Next Oldest | Next Newest >  
djmullen



Posts: 327
Joined: Jan. 2006

(Permalink) Posted: Aug. 28 2009,00:18   

[quote=deadman_932,Aug. 27 2009,19:16]        
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ETA: That last bit is purely rhetorical, Billy. Anyone that would write their own book review (as you did) under a fake name at Amazon...well, it's a moot point. Try changing, now.

Speaking of which, Clive missed this reference:      
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57
djmullen
08/27/2009
1:44 am


denyse, kairosfocus and reader from riesel, are you aware that you’re using the word “ratchet” instead of “latching”?

Darwinian evolution does “ratchet” information into the DNA. It’s been described that way by scientists for decades.

It does this ratcheting through the simple technique of making many copies of successful DNA strings and letting natural selection get rid of any unsuccessful mutations to those strings – such as restoring a former incorrect letter.

This is EXACTLY what happens in Dawkins’ program or any other program that successfully mimics evolution. That is why Dawkins did not have to put any kind of latching into his program – the latching / ratcheting is inherent in Darwinian evolution and his program merely simulates one part of it.

Spiny Norman: Dawkins wrote “Weasel” as a pedagogical tool to demonstrate how the cumulative selection that is used by Darwinian evolution is almost infinitely faster than the type of “all-at-once” selection that creationists and IDists typically use. (You know, where they calculate that it would take 20^100 tries to find a 100 amino acid length protein by chance or 4^150 tries to find a 150 base pair long stretch of DNA by chance.) Because it was a teaching tool, he selected a specific target for it to find rather than confuse the issue by cobbling together some sort of moving target.

However, as I’ve written on this blog, if you re-write the program to look into an external file for the “target”, you can change that target whenever you wish and the program will continue to find the new strings just as quickly as it finds the fixed “Methinks it is like a weasel”.

But then he killed these next two messages:    
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68
djmullen
08/27/2009
5:01 am
Your comment is awaiting moderation.


feebish @ 63: “I don’t understand why so many here are arguing against letting Dr Dawkins release his program.”

The real question is why so many are demanding that Dr. Dawkins produce a piece of throwaway code written over 20 years ago when his description of the program is clear enough to enable any mildly competent programmer to duplicate it.

I think the basic problem is that it has been duplicated many times and it works as advertised.

I suspect that a lot of ID Defenders have duplicated the code and found to their dismay that it works as advertised. What to do, what to do?

Well, there’s a saying in the legal profession: “If the law is on your side, pound on the law. If the facts are on your side, pound on the facts. And if neither is on your side, pound on the table.”

This demand for the original code is the ID version of pounding on the table. It distracts from the fact that the program is easily written from the description and works as advertised.

I predict that the next tactic will be to demand that Dawkins produce his original birth certificate. And you know what? It will prove that he was born in Kenya!


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69
djmullen
08/27/2009
5:31 am
Your comment is awaiting moderation.


Kairosfocus @ 66:
“2 –> IN EVERY INSTANCE WHERE A LETTER GOES CORRECT IN ANY ONE GENERATION, IT REMAINS SO IN ALL FURTHER SAMPLES UNTIL THE PROGRAM HITS THE FULL TARGET.”

How do you know this? Have you EVER seen a run which displayed EVERY member of every generation?

Remember that because Weasel (and evolution) makes many copies of every improved piece of DNA, a mutation can revert any single improved copy back to its original form and that non-optimal copy just gets discarded by natural selection.

“3 –> On law of large no’s [the correct form of the layman's crude "law of averages"], that strongly supports the inference that the samples do not revert because the generational champions preserve correct letters very strongly.”

You seem to be agreeing with me here. Evolution’s secret is to make lots of copies of successful organisms so an occasional defective copy can be lost through natural selection without adversely affecting the main population.

“4 -> The computer examines the mutant nonsense phrases, the ‘progeny’ of the original phrase, and chooses the one which, however slightly, most resembles the target phrase, METHINKS IT IS LIKE A WEASEL . . . . What matters is the difference between the time taken by cumulative selection, and the time which the same computer, working flat out at the same rate, would take to reach the target phrase if it were forced to use the other procedure of single-step selection”

Right, that’s the secret to Darwinian evolution. You get an organism that barely reproduces. You make lots of copies of it and some of those copies inevitably mutate. If any one of those mutated copies out reproduces the original, lots of copies are made of it and it eventually replaces the original. If one of the copies suffers another mutation that knocks it back to the original, it’s discarded by natural selection. This is basic Darwinian Evolution.

“5 –> Weasel is targetted search that rewards mere proximity of non-functional phrases through a process of random variation of a seed to create a population and artificial selection based on mere proximity to a set target.”

Weasel is a pedagogical program written to illustrate the difference between cumulative selection (which it uses) and the type of all-at-once selection ID people seem to think evolution uses. Dawkins gave it a fixed target to simplify the program and help illustrate how cumulative selection works.

As I’ve mentioned elsewhere, you can put that target statement into a separate file and change it to your heart’s content and Weasel will ALWAYS converge on it. What you call “proximity to a target” corresponds to “ability to reproduce” in the real world. Think of the target string as being a very very good reproducer and the original random string as something that just barely copies itself. The closer the organism gets to the target string, the better it reproduces.
I think I’ll quit here and see if you have a response to what I’ve said so far.

All examples from (or should have been in) the "Where's the code for the goddamn weasel?" thread

  
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