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Author | Topic: About New Lamarckian Synthesis Theory | |||||||||||||||||||||||||||||||||||||||
jar Member (Idle past 423 days) Posts: 34026 From: Texas!! Joined: |
If the environment was actually causing as opposed to filtering changes then the same changes should show up in all of a population living in the same environment; however evidence refutes that position.
As was pointed out in Message 57:
quote: It is a matter of filtering, not causation. The mutations continue and there will still be dark gray and tan mice born that will be filtered by the environment.Anyone so limited that they can only spell a word one way is severely handicapped!
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Thank you Percy.I will try by my poor knowledge of biology.I think all the relevant data are well expressed in WIKIPEDIA.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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Why evolutionists are not willing to discuss Lamarckian scenario in evolution? Because it has been falsified by the evidence.
Doesn’t it show that scientists, at least in this forum, are only caring for to protect at any cost the sacred caw of exclusive random mutations? There is nothing to protect. The evidence points to random mutations which is why we conclude that mutations are random. You, on the other hand, ignore the evidence and keep pushing guided mutations which are not supported by evidence. Why do you do that?
Epigenetic inheritance . . . Epigenetic inheritance does not change DNA sequence nor does it explain the differences between species (e.g. the differences between humans and chimps). I really don't see how it is on topic in a discussion dealing with the question of random vs. guided mutations.
Classic evolutionists have to face this fact: ANY MUTATION DETRIMENTAL, NEUTRAL OR USEFUL IS A GUIDED BY THE ENVIRONMENT MUTATION. Mutations are caused by mechanisms that are incapable of determining if the mutation will be harmful, neutral, or beneficial. That is why these mechanisms will produce mutations that confer antibiotic resistance when no antibiotics are present.
Surely they had ignored guided mutations, but not excluded it. Hardly. You really need to read this paper: http://www.genetics.org/content/28/6/491.full.pdf+html Luria and Delbruck tested for both random and guided mutations. The results of the experiment pointed to random mutations.
"Soma to germ-line feedback In the 1970s the immunologist Ted Steele, formerly of the University of Wollongong, and colleagues, proposed a neo-Lamarckian mechanism to try to explain why homologous DNA sequences from the VDJ gene regions of parent mice were found in their germ cells and seemed to persist in the offspring for a few generations. The mechanism involved the somatic selection and clonal amplification of newly acquired antibody gene sequences that were generated via somatic hyper-mutation in B-cells. The mRNA products of these somatically novel genes were captured by retroviruses endogenous to the B-cells and were then transported through the blood stream where they could breach the soma-germ barrier and retrofect (reverse transcribe) the newly acquired genes into the cells of the germ line." [emphasis mine] The somatic hyper-mutation that produced those sequences were random with respect to fitness.
The effects of an animal's environment during adolescence can be passed down to future offspring, according to two new studies. If applicable to humans, the research, done on rodents, suggests that the impact of both childhood education and early abuse could span generations. The findings provide support for a 200-year-old theory of evolution that has been largely dismissed: Lamarckian evolution, which states that acquired characteristics can be passed on to offspring. That is epigenetics. It does not involve a change in DNA sequence.
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Taq Member Posts: 10085 Joined: Member Rating: 5.1
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But what is the evidence for random mutations? Beneficial mutations occur in the absence of the environment in which they are beneficial. For example, mutations conferring antibiotic and bacteriophage resistance occur in the absence of antibiotics and bacteriophage. Even more, we can study the exact mechanisms that are producing these mutations. In the following study, they measured the fit between the incoming nucleotide and polymerase responsible for extinding the DNA molecule. They found that there is a loose fit between the substrate and the enzyme resulting in the random production of mutations.
quote: Guess what gene they used to measure the mutation rate? That would be the tonB gene, the gene that was responsible for bacteriophage resistance in the Luria and Delbruck paper that I referenced above. We understand down to the angstrom why mutations are random. What do you have to show for guided mutations?
The Baldwin effect it is another argument for guided mutations and against randomness.
The Baldwin effect is selection only. It does not deal with how mutations occur. The Baldwin effect results in selection for variants that are able to learn a behavior more quickly or more effectively. The production of those variants is still reliant on random mutations.
The interesting thing is that real scientist discuss easily about diversions of evolutionary theories in contrast of participants in evolutionary forums. Real scientists do not push ideas that are not backed by evidence, and even worse, ideas that are contradicted by evidence. They also do not confuse epigenetics and random mutagenesis as you do. Edited by Taq, : No reason given.
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nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 4.5 |
I think the way Zi Ko is looking at this is that if a behavior can be considered an acquired characteristic, then if that behavior is heritable it could be considered Lamarckian because it would be a heritable acquired characteristic, and it could be considered guided by the environment because the environment could have trained in the behavior, either naturally in the wild or experimentally through laboratory training, or through a classroom, and just through normal day-to-day activities.
Well, fair enough. However, it is not the specific mutation that is guided, and that's what zi ko is getting wrong. One could say that there is guidance toward mutations that support the particular behavior, and fair enough on that, too. The tradition view would be to call that filtering by natural selection, rather than guidance. If zi ko is trying to make a case against the Darwinian account, then he needs to do better than that.Jesus was a liberal hippie
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nwr Member Posts: 6412 From: Geneva, Illinois Joined: Member Rating: 4.5 |
nwr writes: No, it isn't. zi ko writes:
What's to prove?Can you or anny body else prove this assertion? The Baldwin effect is fully accounted for by standard Darwinian theory, as explained in the Wikipedia page that I linked to.Jesus was a liberal hippie
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Not all the copies are perfect, some have mutations. I agree with the rest. But what would you say if add: ... mutations that are guided by environment? How can you exclude this scenario? Just by saying that 'all scientists believe so'? You must have evidence for it to say so.
If the environment was actually causing as opposed to filtering changes then the same changes should show up in all of a population living in the same environment; however evidence refutes that position.
Environment is never the same for different members.
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Dr Jack Member Posts: 3514 From: Immigrant in the land of Deutsch Joined: Member Rating: 8.3 |
Epigenetics is not Lamarckian. It shares some small piece in common but it does not allow Lamarck's method of change. There are two fundamental reasons for this:
1. Epigenetic change is not accretional. Epigenetic switches are there or not based on genetic sequences, changing epigenetic state does not create new opportunities for new epigenetic changes. This means that epigenetic change can only alter an organism's phenotype within finite limits. 2. There's a major part of Lamarck's ideas that tends to be forgotten. Lamarck believed in a kind of "chain of being" where new organisms rose up the chain in a largely linear fashion, so that "primitive" organisms such as, say, a leech were not evolved for a niche but simply less advanced along a chain of being that we had long since crossed. Obviously, epigenetics provides no support for this notion.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Epigenetic inheritance does not change DNA sequence nor does it explain the differences between species (e.g. the differences between humans and chimps). I really don't see how it is on topic in a discussion dealing with the question of random vs. guided mutations.
Epigenetic inheritance gives the first part of a mechanism of environmental effect on outer and some times deep genome. It paves the way for deep genome mutatations relevant to organism's needs. Of course nobody would expect to see such mutations in action.
Mutations are caused by mechanisms that are incapable of determining if the mutation will be harmful, neutral, or beneficial. That is why these mechanisms will produce mutations that confer antibiotic resistance when no antibiotics are present.
I almost agree.But environment knows about which mutations will be needed even for the near future in a range of propailities.
Why do you do that?
Because you ignore a possible scenario of evolution in spite of very little evidence against it.
Luria and Delbruck tested for both random and guided mutations. The results of the experiment pointed to random mutations.
This experiment refers to one cell organisms, where randomess is an economical mechanism for nature to choose. You should bring evidences from multicellular organisms.
The somatic hyper-mutation that produced those sequences were random with respect to fitness.
If you go a bit earlier you will see that environment had caused hyper mutation, at the time it needed it.
That is epigenetics. It does not involve a change in DNA sequence You could see that change if you had time. Edited by zi ko, : No reason given.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
The "Baldwin effect" is better understood in evo-devo (evolutionary developmental biology) literature as a scenario in which a character or trait change occurring in an organism as a result of its interaction with its environment becomes gradually assimilated into its developmental genetic or epigenetic repertoire (Simpson, 1953; Newman, 2002). In the words of Daniel Dennett, From above we can deduct that 1. Environmental information can result deep genome changes. 2. The Selection mechanism is present.3. There was for some time a wrinkle in orthodox Darvinism. what is the new evidence that the wrinkle has gone or this not just a belief? Where is the proof that relevant mutations were not guided? Thanks to the Baldwin effect, species can be said to pretest the efficacy of particular different designs by phenotypic (individual) exploration of the space of nearby possibilities. If a particularly winning setting is thereby discovered, this discovery will create a new selection pressure: organisms that are closer in the adaptive landscape to that discovery will have a clear advantage over those more distant. (p. 69,[1] quoting Dennett, 1991).....According to Dennett, recent work has rendered the Baldwin effect "no longer a controversial wrinkle in orthodox Darwinism" (p. 69[1]).
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
1. Epigenetic change is not accretional. Epigenetic switches are there or not based on genetic sequences, changing epigenetic state does not create new opportunities for new epigenetic changes. This means that epigenetic change can only alter an organism's phenotype within finite limits.
Epigenetic changes pave the way to relevant epig. changes.
2. There's a major part of Lamarck's ideas that tends to be forgotten. Lamarck believed in a kind of "chain of being" where new organisms rose up the chain in a largely linear fashion, so that "primitive" organisms such as, say, a leech were not evolved for a niche but simply less advanced along a chain of being that we had long since crossed. Obviously, epigenetics provides no support for this notion.
That is why i am talking about the NEW SYNTHESIS OF LAMARCKISM.
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jar Member (Idle past 423 days) Posts: 34026 From: Texas!! Joined: |
jar writes: I agree with the rest. But what would you say if add: ... mutations that are guided by environment? How can you exclude this scenario? Just by saying that 'all scientists believe so'? You must have evidence for it to say so. Not all the copies are perfect, some have mutations. If you said that I would laugh, laugh loudly and heartily. And I presented the evidence and and you even quoted part of my evidence. But did you actually read it?
If the environment was actually causing as opposed to filtering changes then the same changes should show up in all of a population living in the same environment; however evidence refutes that position.
Environment is never the same for different members. Nonsense, utter nonsense. Let me repeat the example for you.
quote: The environment did absolutely nothing to cause the mutations.Anyone so limited that they can only spell a word one way is severely handicapped!
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Before you start laughing i suggest you to make some thinking firstly.Serious scientists have different wiews than you on the matter.(See O.P) I would be most grateful to you if you could give me some evidences concerning your stiff belief on random mutations, so to restore my own shattered belief on it.
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NoNukes Inactive Member |
I would be most grateful to you if you could give me some evidences concerning your stiff belief on random mutations. It is fair to note that jar did not provide any evidence supporting the fact that mutations are random with respect to fitness. But that scarcely matters, because others have done so, and you've ignored what they have presented. As for the OP, it does leave room open to argue about some Lamarckian aspects to epigenesis, but even that modification might well be random with respect to fitness even if the mutations themselves are induced by external stimuli. In order to have a case, you need to show not just that the rate of mutations is susceptible to environmental pressure, but that the fitness of those mutations is also susceptible to the same pressure.Under a government which imprisons any unjustly, the true place for a just man is also in prison. Thoreau: Civil Disobedience (1846) The apathy of the people is enough to make every statue leap from its pedestal and hasten the resurrection of the dead. William Lloyd Garrison. It's not too late to register to vote. State Registration Deadlines
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jar Member (Idle past 423 days) Posts: 34026 From: Texas!! Joined: |
I did provide evidence just above but will happily repeat it yet again.
quote: Mice had baby meeces that were both tan and dark gray in the same litter.Anyone so limited that they can only spell a word one way is severely handicapped!
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