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Author Topic:   Doesn't Natural Selection lead to Specified Complexity?
Taq
Member (Idle past 34 days)
Posts: 8488
Joined: 03-06-2009


Message 22 of 138 (615468)
05-13-2011 11:22 AM
Reply to: Message 20 by Peter
05-13-2011 6:20 AM


Re: So: 'If it was designed intelligently then it is the product of intelligent design.'
Drift is not a function of the environment (if I understand the term correctly) since the prevalence of that 'trait' is not dependent on environment (if it were it would be bound up in the natural selection).

Yes and no. There are some mutations that make no changes in function or phenotype (e.g. synonymous mutations). There are also mutations that produce changes in phenotype but such changes do not result in a change in fitness. In the latter case the environment does play a role in determining selective pressure and the prevalence of a trait.

If a natural process can produce a pattern, then specified complexity is not a marker for design . . .

OR . . . . evolution is a designer. That always confuses the ID supporters.


This message is a reply to:
 Message 20 by Peter, posted 05-13-2011 6:20 AM Peter has responded

Replies to this message:
 Message 25 by Peter, posted 05-16-2011 7:50 AM Taq has responded

  
Taq
Member (Idle past 34 days)
Posts: 8488
Joined: 03-06-2009


Message 29 of 138 (615778)
05-16-2011 5:52 PM
Reply to: Message 25 by Peter
05-16-2011 7:50 AM


Re: So: 'If it was designed intelligently then it is the product of intelligent design.'
In the latter case that you mentioned, where a phenotype change does not alter fitness -- but selective pressure still applies ... that seems a contradiction.

You need to carefully parse what I said. I stated that the environment determines which changes are under selective pressure. The environment determines which mutations are under negative, positive, or neutral selection. I am relating all of this back to a previous post where you stated:

"Drift is not a function of the environment (if I understand the term correctly) since the prevalence of that 'trait' is not dependent on environment (if it were it would be bound up in the natural selection)."

The environment does determine which mutations are neutral, and therefore determines the probability of that trait being passed on to the next generation.


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 Message 25 by Peter, posted 05-16-2011 7:50 AM Peter has responded

Replies to this message:
 Message 31 by Peter, posted 05-17-2011 4:36 AM Taq has responded

  
Taq
Member (Idle past 34 days)
Posts: 8488
Joined: 03-06-2009


Message 30 of 138 (615780)
05-16-2011 6:00 PM
Reply to: Message 27 by Peter
05-16-2011 11:49 AM


Re: So: 'If it was designed intelligently then it is the product of intelligent design.'
But how does that make drift a part of the environment?
Drift isn't an event.

Drift is a mathematical model which describes the spread of mutations that do not affect fitness in a given environment. Which mutations are neutral is a function of the environment just like the environment determines which mutations are beneficial and which are detrimental.

If we were to view natural selection (as I do) as a process which acts iteratively on a set of environmental effects & a set of genetic mutations (within a population of interest) then that process must be deterministic, else it is not a process at all.

Natural selection is never deterministic. It is always probabilistic. The game of craps is a good analogy. You have the highest probability of rolling a 7 on any given roll, but this doesn't mean that you will roll a 2 or 12 occasionally. The same for selection. Sometimes beneficial mutations are not passed on, and other times detrimental mutations are passed on. For beneficial mutations the odds are in their favor while the odds are against detrimental mutations. For neutral mutations there are even odds. All mutations fall somewhere in this spectrum.


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 Message 27 by Peter, posted 05-16-2011 11:49 AM Peter has responded

Replies to this message:
 Message 32 by Peter, posted 05-17-2011 4:42 AM Taq has responded

  
Taq
Member (Idle past 34 days)
Posts: 8488
Joined: 03-06-2009


Message 35 of 138 (615849)
05-17-2011 3:33 PM
Reply to: Message 31 by Peter
05-17-2011 4:36 AM


Re: So: 'If it was designed intelligently then it is the product of intelligent design.'
Nuetrality is not determined by the environment, . . .

Yes, it is. The effect that a mutation has on fitness is determined by the environment, and this includes neutral effects. A mutation conferring antibiotic resistance in an environment with antibiotics is a beneficial mutation. If antibiotics are removed from the environment then that mutation may very well become neutral or slightly detrimental. It is the environment which determines this.


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 Message 31 by Peter, posted 05-17-2011 4:36 AM Peter has responded

Replies to this message:
 Message 38 by Peter, posted 05-18-2011 6:27 AM Taq has responded

  
Taq
Member (Idle past 34 days)
Posts: 8488
Joined: 03-06-2009


Message 36 of 138 (615851)
05-17-2011 3:37 PM
Reply to: Message 32 by Peter
05-17-2011 4:42 AM


Re: So: 'If it was designed intelligently then it is the product of intelligent design.'
Nuetrality is not a relationship to the environment, but an absence of a relationship.

How can you determine if a mutation is neutral without first having the environment interact with the population through evolutionary mechanisms?

There seems to be a rough agreement that the 'specified' part could equally apply to evolutionarily generated entities as IDed ones.

That leaves complexity.

The specification in ID rhetoric is nothing more than a sharpshooter fallacy. They draw a bull's eye around the arrow, or in the case of the actual biological systems they draw the bull's eye around the current DNA sequence.

As to complexity, this is exactly what we would expect to see in a top-down design process like evolution. You are bound to produce Rube Goldberg mechanisms when the design process is blind to the actual specifics of the design. The sign of intelligent design is often simplicity, not complexity.


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 Message 32 by Peter, posted 05-17-2011 4:42 AM Peter has responded

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Taq
Member (Idle past 34 days)
Posts: 8488
Joined: 03-06-2009


Message 41 of 138 (615927)
05-18-2011 11:35 AM
Reply to: Message 38 by Peter
05-18-2011 6:27 AM


Re: So: 'If it was designed intelligently then it is the product of intelligent design.'
If there are no anti-biotics in the environment, then a mutation that confers resistance to anti-biotics is nuetral -- agreed.

But it is nuetral because it does not react with the environment -- that is there is an absence of a relationship rather than the existence of a nuetral relationship.

These mutations do react with the environment whether or not there are antibiotics present. These mutations occur in proteins that are involved in protein synthesis, cell wall catabolism, etc. Netrality is determined by whether or not these interactions result in a change in fitness.


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 Message 38 by Peter, posted 05-18-2011 6:27 AM Peter has responded

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 Message 42 by Peter, posted 05-18-2011 2:31 PM Taq has responded

  
Taq
Member (Idle past 34 days)
Posts: 8488
Joined: 03-06-2009


Message 44 of 138 (615952)
05-18-2011 2:46 PM
Reply to: Message 42 by Peter
05-18-2011 2:31 PM


Re: So: 'If it was designed intelligently then it is the product of intelligent design.'
...and if there is a change in fitness then there is a relationship between the mutation and the environment, otherwise there isn't.

It is the relationship between the mutation and the environment which determines if a mutation is neutral, beneficial, or detrimental. There is no way to determine if a mutation is neutral without observation of how that mutation relates to the environment. There is always a relationship between DNA sequence and environment.

Natural selection operates in some way on a set of mutations which DO relate to the environment with the end result being entities which appear to have been designed for that very environment.

Exactly.


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 Message 42 by Peter, posted 05-18-2011 2:31 PM Peter has responded

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 Message 45 by Peter, posted 05-18-2011 2:51 PM Taq has responded

  
Taq
Member (Idle past 34 days)
Posts: 8488
Joined: 03-06-2009


Message 46 of 138 (615956)
05-18-2011 3:03 PM
Reply to: Message 45 by Peter
05-18-2011 2:51 PM


Re: So: 'If it was designed intelligently then it is the product of intelligent design.'
Having a relationship which is nuetral (as you I think put it) or having an absence of a relationship amount to the same thing i.e. those mutations are not acted upon by natural selection.

They are not the same thing. There is no relationship between a mutation that occurs in an ostrich and deep sea environments because an ostrich does not live in a deep sea environment. However, each and every mutation that occurs in an ostrich offspring (including neutral ones) have a relationship with the environment they do live in. For neutral mutations, this relationship causes the ratio of neutral mutations to stay the same on average. Natural selection is all about the probability of a mutation being passed on. For neutral mutations, natural selection produces a 50-50 probability.


This message is a reply to:
 Message 45 by Peter, posted 05-18-2011 2:51 PM Peter has responded

Replies to this message:
 Message 47 by Peter, posted 05-18-2011 3:11 PM Taq has responded

  
Taq
Member (Idle past 34 days)
Posts: 8488
Joined: 03-06-2009


Message 48 of 138 (615969)
05-18-2011 4:07 PM
Reply to: Message 47 by Peter
05-18-2011 3:11 PM


Re: So: 'If it was designed intelligently then it is the product of intelligent design.'
It won't be 50-50 if there are other mutations which are being selected for or against.

All population genetics assume an ideal population. A neutral mutation has the same chance of being linked to a detrimental or beneficial allele so the it does average out to 50-50 for all neutral mutations in an ideal population.

Nuetral meaning that they have no affect on fitness ... which in turn means they have no relationship to the environment.

I have addressed this quite a few times. This is false. It is the relationship between the mutation and the environment that determines the effect on fitness, even if that effect results in no net change.

The ostrich mutation MIGHT have a relationship to a deep sea environment (if for example it changed the ability to absorb oxygen from sea water) but not to the environment that the ostrich IS in.

Right. So the neutrality of a mutation is determined by the relationship between the mutation and the environment that the organism is in.


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 Message 47 by Peter, posted 05-18-2011 3:11 PM Peter has responded

Replies to this message:
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