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Author Topic:   Doesn't Natural Selection lead to Specified Complexity?
Wounded King
Member (Idle past 3157 days)
Posts: 4149
From: Edinburgh, Scotland
Joined: 04-09-2003


Message 73 of 138 (617286)
05-27-2011 8:34 AM
Reply to: Message 71 by Percy
05-27-2011 7:56 AM


Re: So: 'If it was designed intelligently then it is the product of intelligent design.'
And once any alleles find themselves in circumstances where they do impact reproductive success then by definition they're no longer drift alleles.

I don't really see this. Genes that have a selective benefit or detriment can still be subject to genetic drift, otherwise all beneficial mutations would be maintained in populations once they arose, which would make the effects of selection for a given allele in a given environment truly deterministic. The stochastic forces that produce genetic drift can affect any allele.

Drift is an effect of essentially random sampling with regard to allelic fitness. The tack you are taking seems to take the contextual nature of mutations to a ludicrous extreme such that the fitness of any allele would be determined by the specific situation of the individual organism carrying it. So any allele of an organism that died before reproducing would have a neutral fitness. But these are population genetics concepts and they only really work in terms of populations.

There are no 'mutations responsible for drift', drift is not a mutational phenomenon it is a phenomenon of random sampling. Mutation simply creates the alleles, whatever their fitness, upon which drift and selection operate.

TTFN,

WK


This message is a reply to:
 Message 71 by Percy, posted 05-27-2011 7:56 AM Percy has responded

Replies to this message:
 Message 74 by Percy, posted 05-27-2011 9:29 AM Wounded King has responded

  
Wounded King
Member (Idle past 3157 days)
Posts: 4149
From: Edinburgh, Scotland
Joined: 04-09-2003


Message 75 of 138 (617290)
05-27-2011 9:49 AM
Reply to: Message 74 by Percy
05-27-2011 9:29 AM


Re: So: 'If it was designed intelligently then it is the product of intelligent design.'
But in many cases people don't distinguish between alleles and mutations, it often being the case that the term allele isn't familiar and so the term mutation stands in for allele, and while I don't know if that is the case here, what I fear is that Peter is being subjected to this same sort of nit-picky treatment where something stated insufficiently precisely from your point of view is criticized as if it were wrong.

There aren't any alleles responsible for drift either. My whole point was that the fitness of any given allele is incidental to drift, drift occurs regardless of the fitness of alleles. Drift and selection are two separate factors that can work independently, in accord or in competition to alter the frequency of alleles in a population.

If you are trying to say that genetic variation, i.e. more than one allele, is required for drift or selection to operate then of course I agree. In a perfectly homogeneous population there will be no effect from drift or selection and a de novo mutation will be required before they can operate. Is that your point?

There's a guy in my group at work who is brilliant, true genius level, but he demands an impossible level of precision in all technical communication and is widely despised.

I'm not that smart but I'll try my best to compete, 'never knowingly under nit-picked' that's my motto.

TTFN,

WK


This message is a reply to:
 Message 74 by Percy, posted 05-27-2011 9:29 AM Percy has acknowledged this reply

  
Wounded King
Member (Idle past 3157 days)
Posts: 4149
From: Edinburgh, Scotland
Joined: 04-09-2003


Message 86 of 138 (619724)
06-11-2011 5:00 PM
Reply to: Message 85 by SavageD
06-11-2011 4:38 PM


Re: Doesn't Natural Selection lead to Specified Complexity?
It refers to survival of the fittest, which is in fact quite broad rather than specific.

While the general concept of 'survival of the fittest' may be broad, the exact adaptations that confer fitness in a given context can be quite specific.

To be short, the "specified complexity" your referring to is in fact, a figment of your imagination, it only appears to result in "specified" complexity.

A lot of us would agree with you, but it is a figment created by IDists suited to produce a need for the very sort of intelligent agency you suggest.

It is not simply the selection process that allows organisms to adapt & survive, but the underlying processes & mechanisms inside the organism....which just happens to be very "specific".

This would be a good time to show some evidence suggesting this. The vast majority of evidence shows that the mechanisms creating genetic variation, basically the various different forms of mutation, are not very specific at all and that the principle constraints are applied post hoc by natural selection. For example look at experiments for the evolution of bacterial resistance where the trait can be shown to arise in cultures not exposed to the antibiotic in line with the frequency expectations of random mutation.

TTFN,

WK


This message is a reply to:
 Message 85 by SavageD, posted 06-11-2011 4:38 PM SavageD has responded

Replies to this message:
 Message 88 by SavageD, posted 06-11-2011 7:28 PM Wounded King has responded

  
Wounded King
Member (Idle past 3157 days)
Posts: 4149
From: Edinburgh, Scotland
Joined: 04-09-2003


Message 92 of 138 (619755)
06-12-2011 4:18 AM
Reply to: Message 88 by SavageD
06-11-2011 7:28 PM


Re: Doesn't Natural Selection lead to Specified Complexity?
True, but, it is because these mechanism are specific that it points to an intelligent agent. Systems created by an intelligent agent tend to be very specific.

Well as I said, the mechanisms aren't specific some of the resulting adaptational outcomes are however. So you may be right that systems created by an intelligent agent tend to be specific, but if so then we have considerable evidence that the results of mutation and selection are exceptions to this overall trend.

Fair enough, though, I'll like to point out that your contradicting the first point you made here: "the exact adaptations that confer fitness in a given context can be quite specific."

Not a contradiction at all, the adaptive mutations that confer fitness may be specific but the mechanisms by which they arise, principally random mutation, are non-specific. It is the environment with which the various genomes interact that imposes apparent specificity on the varieties that thrive, after they have arisen, through differential reproductive success.

So multiple entirely maladaptive or non-adaptive variants are being produced at the same time as adaptive variants, but the particular pattern in which they are retained in the gene pool is heavily influenced by the specific environment in which they exist.

Your not making sense here...

What I'm saying is that most of the people who talk about specified complexity are IDists, it isn't a widely used concept in evolutionary biology. And the reason they do is to use the term specification to insert a requirement for an intelligent agency, exactly the same argument you are trying to make. They use similar approaches talking about genetic information, Werner Gitt has a definition of information which explicitly requires it to have a mental origin, thoroughly stacking the deck in favour of intelligent agency again.

(1) The same mechanisms can found in many other organisms (namely ones of the same taxonomic group).

How on earth is that specific? The same mechanisms can usually be found outside of that taxonomic group as well, unless you are basing you taxonomy solely on such mechanisms.

It would help if you yourself were more specific, after all a taxonomic 'group' could be anything from a subspecies to a kingdom or even a domain.

(2) Altering one of more of these mechanisms (DNA for example) can lead to the organisms death or can leave them at a major disadvantage to the environment (a deformed leg for example).

Well it can but most of the evidence suggests that in general it doesn't. We can change an organisms DNA significantly and see no obvious effects on its viability while on the other hand there are some single nucleotide mutations which are lethal at very early stages of embryonic development.

So again it is hard to see where this suggests any particular specificity in the mechanisms giving rise to the mutations.

(3) These mechanisms are connected to other intricate components, these components must also be connected in a certain sequence. Without this sequence of interconnected parts the organism may die or it may not function properly.

Again some evidence and some speciicity on your part would be good. I'm not even sure what 'mechanisms' you are talking about now, you seem to be using the term interchangeably for both the systems originating the mutations and the systems resulting from mutation and selection.

TTFN,

WK


This message is a reply to:
 Message 88 by SavageD, posted 06-11-2011 7:28 PM SavageD has not yet responded

  
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