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Author | Topic: About New Lamarckian Synthesis Theory | |||||||||||||||||||||||||||||||||
zi ko Member (Idle past 3647 days) Posts: 578 Joined: |
Why evolutionists are not willing to discuss Lamarckian scenario in evolution?
I understand that as Lamarckism is an evolutional theory , any discussion about it would weaken the thesis of evolution theory against ID. But should this be an excuse for the scientists for not willing to discuss it? 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? This is very disappointing to me. Of course nobody supports that mutations, insertions, transpositions repairing etc, are conscious acts towards fitness, no more than of the parts of a working machine made by an intelligent man. Here in the case of existing living creatures we have to accept either a Superior Intelligence, or that Natural Forces and Laws are able to lead to these creatures. This is the real big problem we have to face, instead of quarreling around. We can’t stop in between, if we want to be sincere. In Wikipedia we read:
Epigenetic inheritance Forms of 'soft' or epigenetic inheritance within organisms have been suggested as neo-Lamarckian in nature by such scientists as Eva Jablonka and Marion J. Lamb. In addition to 'hard' or genetic inheritance, involving the duplication of genetic material and its segregation during meiosis, there are other hereditary elements that pass into the germ cells also. These include things like methylation patterns in DNA and chromatin marks, both of which regulate the activity of genes. These are considered "Lamarckian" in the sense that they are responsive to environmental stimuli and can differentially affect gene expression adaptively, with phenotypic results that can persist for many generations in certain organisms. Although the reality of epigenetic inheritance is not doubted (as many experiments have validated it), its significance to the evolutionary process is uncertain. its significance to the evolutionary process is uncertain. Yes I agree but what is certain about in classic theory except natural selection? Specially as it regards evolution by random mutations? Only indications and beliefs not substantiated. The same it applies to Lamarckism, though the evidence is growing up all the time and it seems that it would incorporate randomness, as a helpful mechanism of evolution amongst others, in the New Lamarckian Synthesis theory. Of course we know about clearly random mutations caused by X-rays, chemicals etc, But most of them are deleterious and in any case not substantial to evolution. Classic evolutionists have to face this fact: ANY MUTATION DETRIMENTAL, NEUTRAL OR USEFUL IS A GUIDED BY THE ENVIRONMENT MUTATION. Not a single scientific work up to now had convincingly excluded it in all relevant described cases. Surely they had ignored guided mutations, but not excluded it. Let me relate some relevand data:
"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." "A Comeback for Lamarckian Evolution?Two new studies show that the effects of a mother's early environment can be passed on to the next generation. Wednesday, February 4, 2009 Silencing DNA: Adding methyl groups to specific spots in the genome can alter the expression of marked genes. The process, known as DNA methylation, is one mechanism of epigenetic change, heritable change that does not alter the sequence of DNA itself. In this image, colored bars represent the bases that make up a strand of DNA, while the green circles represent methylation. Technology Review 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. "....The results are extremely surprising and unexpected," says Li-Huei Tsai, a neuroscientist at MIT who was not involved in the research. Indeed, one of the studies found that a boost in the brain's ability to rewire itself and a corresponding improvement in memory could be passed on. "This study is probably the first study to show there are transgenerational effects not only on behavior but on brain plasticity." The results of both studies are likely to be controversial, perhaps resurrecting a centuries-old debate. "It's very provocative," says Lisa Monteggia, a neuroscientist at the University of Texas Southwestern Medical Center, in Dallas. "It goes back to two schools of thought: Lamarck versus Darwin." "But the research now makes it more plausible that these things may be real and may be based in molecular mechanisms." Edited by zi ko, : No reason given. Edited by Admin, : Reformat so it's easier to tell Zi Ko's own words from the words he quotes. Edited by Admin, : Correct spelling error in title.
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zi ko Member (Idle past 3647 days) Posts: 578 Joined: |
I intent to discuss mainly epigenetic inheritance together with comparing the existing evidence for random mutations useful to evolution vs guided mutations through environmental effect on genome.
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zi ko Member (Idle past 3647 days) Posts: 578 Joined: |
Perhaps because there isn't a lot of evidence for it. But what is the evidence for random mutations? Whow science have had decided which mutations are random and not guided?
I would think you would be more likely to find something a bit Lamarckian resulting from the Baldwin effect than from epigenetic inheritance.
Yes i agree. The Baldwin effect it is another argument for guided mutations and against randomness.The interesting thing is that real scientist discuss easily about diversions of evolutionary theories in contrast of participants in evolutionary forums. I think it is a psychological phenomenon not difficult to explain.
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zi ko Member (Idle past 3647 days) Posts: 578 Joined: |
Discussing evolutionary theories makes ID more acceptable? Of course not. But it reduces the faith of the followers of classic Theory, which to some is very dangerous to happen.
And were that 'fact' written in a language folks can understand, such as English, they just might try to face it. Very arogant statement...But you just have forgotten to present any evidence for random mutations.
Just what are you hoping to prove?
Nothing more than that i have said in the oponent post and may make some to think about their fixed and unjustifiable beliefs. Edited by zi ko, : No reason given.
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zi ko Member (Idle past 3647 days) Posts: 578 Joined: |
No, it isn't. Can you or anny body else prove this assertion?
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zi ko Member (Idle past 3647 days) Posts: 578 Joined: |
You don't need to bother about my supposed(!) intentions. You just present the evidences of your beliefs if you can.
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zi ko Member (Idle past 3647 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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zi ko Member (Idle past 3647 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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zi ko Member (Idle past 3647 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 3647 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 3647 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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zi ko Member (Idle past 3647 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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zi ko Member (Idle past 3647 days) Posts: 578 Joined: |
Yes. The Gaia hypothesis have some similarities with my views. Leaving out teleological thoughts, i think the whole Universe is a model of intercommuniation, where information exchange is the real essense and the defining expression of life. So the Universe is really alive. In sequence life in Earth, as the end result of this intercommunication depends on this information exchange.Nothing at this sense is random, as randomness itself is a natural, amongst others, sometimes more economical mechanism, to stabilise life ( eg. to preserve communication). .
Edited by zi ko, : No reason given.
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zi ko Member (Idle past 3647 days) Posts: 578 Joined: |
....in a very limited sense, one modification can enable another, but it cannot build new functionality or enable new modifications in the way DNA can.
Who can denay by evidence that this modification is really limited and stops at a level that fits your preconcieved ideas. Maybe the time scale available to make sure deductions about their action on DNA is limited.
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zi ko Member (Idle past 3647 days) Posts: 578 Joined: |
Right. There is not yet proof of epigenetics altering the basic structure of DNA. But we read in WIKIE:
" ...then some epigenetic changes are inherited from one generation to the next.[12] This raises the question of whether or not epigenetic changes in an organism can alter the basic structure of its DNA (see Evolution, below), a form of Lamarckism."So the question at least had been raised. We know that up to now nobody had described a random mutation in action leading to a new species and the explanation given by Modern Synthesis Theory in multicellular organisms is the big timescale necessary for this to be seen. So random mutations in metazoa is an unfalsifiable theory. This explanation can be given for guided mutations. Maybe we will be luckier than Darwinists were. Edited by zi ko, : No reason given. Edited by zi ko, : No reason given.
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