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Member (Idle past 1736 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
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Author | Topic: Doesn't Natural Selection lead to Specified Complexity? | |||||||||||||||||||
Peter Member (Idle past 1736 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
Taq writes: 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. Nuetrality is not determined by the environment, it is the position when the environment has no relationship to the mutation in question. It is the absence of a dependency.
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Peter Member (Idle past 1736 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
Nuetrality is not a relationship to the environment, but an absence of a relationship.
The process of natural selection is deterministic, but the 'inputs' or variables upon which it works are not ... so the outcome is not necessarily the same. That's different to rolling dice. Deterministic means: given the same inputs, and the same process the outcome is the same. The process part is natural selection. The inputs part are the random mutations & environmental conditions (possibly events). The random number generator in a compiler is deterministic, but can be used to generate apparently random numbers by seeding the function with different values. However: My original question was about evolution producing entities that would appear to have specified complexity, thus elliminating SC as a marker for intelligent design. There seems to be a rough agreement that the 'specified' part could equally apply to evolutionarily generated entities as IDed ones. That leaves complexity.
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Peter Member (Idle past 1736 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
In what sense are the events that produce drift part of the environment?
Drift is genetic change, which in the description I have used is isolated as a specific and independant variable. Mutations do not happen in response to the changing environment, they happen any way (as part of the error-laden replication process). If a process isn't deterministic, how can it be a process? Are you saying that if one could set up an eco-system identical to the earth of 65,000,000 years ago control every environmental sequence to happen exactly as it did, and trigger exactly the same mutations you would get a different result to what actually happened?
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PaulK Member Posts: 17919 Joined: Member Rating: 6.7 |
quote: Have you forgotten that you defined the environment to include ALL events occurring in the relevant time period? You're asking in what sense events are events, another of those self-answering questions.
quote: How does a stochastic process fail to be a process? Your question doesn't make any sense to me.
quote: Of course not - not that that question has any relevance to my post at all.
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Taq Member Posts: 10302 Joined: Member Rating: 7.1 |
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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Taq Member Posts: 10302 Joined: Member Rating: 7.1 |
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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Peter Member (Idle past 1736 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
Taq writes: 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. 'Simplicity' not 'Complexity' as a marker for intelligent design is something I have often brought up (on this forum in fact several years ago as well as more recently) -- so I'll have to agree with you on that one In reference to nuetrality: WE can only assess nuetrality of a mutation by comparing the features relating to that mutation with the environment. The relationship between that mutation and the environment is non-existent ... that's why it's neutral.
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Peter Member (Idle past 1736 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
Taq writes: 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. 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. Maybe that's just the same thing looked at from different angles though.
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Peter Member (Idle past 1736 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
PaulK writes:
quote: Have you forgotten that you defined the environment to include ALL events occurring in the relevant time period? You're asking in what sense events are events, another of those self-answering questions.
Yes. I separate mutation itself as a separate variable ... because that's how I define my 'mental model'.
quote: How does a stochastic process fail to be a process? Your question doesn't make any sense to me.
There is no such thing as a stochastic process -- there are simply processes which we can only model stochastically because we are unable to accurately model the vast number of variables involved.
quote: Of course not - not that that question has any relevance to my post at all.
In which case the process is deterministic.
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PaulK Member Posts: 17919 Joined: Member Rating: 6.7 |
quote: Trying to change the subject? The point was that the environment as you define it causes drift. And it does so when the course of events favours one allele over another without regard to the effects of that allele.
quote: If this is your assumption of universal determinism again it is trivial and only acts to undermine your point. If it is intended to make a more serious point then it is in need of clarification and support.
quote: I think you mean the PROCESSES because you are including drift and selection in there. Both contribute to the outcome.
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Taq Member Posts: 10302 Joined: Member Rating: 7.1 |
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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Peter Member (Idle past 1736 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
...and if there is a change in fitness then there is a relationship between the mutation and the environment, otherwise there isn't.
No longer sure of the relevance of this bit. If natural selection can operate in such a way that the results of its 'design process' appear to be 'specified' then 'specified complexity' cannot be a marker for intelligent design. 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. So SC cannot be used in support of ID.
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Peter Member (Idle past 1736 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
Environment and Drift:
Not changing the subject. Events in the environment do not cause drift. Genetic mutations happen, largely at random (and possibly from environmental factors like radiation or chemical mutagens), but that aspect is segregated into 'genetic mutation' as a separate/isolated variable. Determinism: In what way does it undermine my point? Processes: I cannot see drift as a process. Some genetic mutations occur which have no relationship to the environment (via natural selection), and some of these mutations become fixed in the population for no particular reason (they just happen to be common, or the population size dwindled or ...) No specific process at work there.
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Taq Member Posts: 10302 Joined: Member Rating: 7.1 |
...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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Peter Member (Idle past 1736 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
I think we just view 'nuetrality' slightly differently ... but not in a way that matters much.
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. The other bit we seem to agree on -- so that's quite good
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