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Author | Topic: About New Lamarckian Synthesis Theory | |||||||||||||||||||||||||||
zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Thanks for the information on the number of vertebrae in giraffe's neck.I would like to have your's and others opinion of what they think of giraffe's long neck and long front legs etc. Are they changes due to epigenetic mechanisms or to DNA sequence changes? and also to what degree they are epigenetic and what was the critical point that they had changed to deep DNA sequence alteration?
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Epigenetic changes do not change into DNA changes.
You surely mean ..."DNA sequence changes". Becouse DNA changes through epigenetics by histone and methylation mechanisms,and the numerous regulation mechanisms are well established.But this was not my question.My question is:Are giraffe's neck and front legs elongation etc epigenetic in nature, or due to DNA sequenc change?And at which point of evoljtion the inevtable initial epigenetic effect was zeroed and was replaced by the DNA sequence change?
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
there is no mechanism for the transfer of epigenetic changes to sequence changes, I don't say so. What i am saying is thatepigenetic changes pave the way( so guide) DNA sequence change. ...no reason to think epigenetics played any major role in giraffe evolution.
It is your belief. You don't answer my question.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Histone packaging and DNA methylation does NOT change DNA sequence. No it doesn't. Just pave the way( so guide) DNA sequence change.
If giraffes were consistently given food on the ground for multiple generations you would not see them suddenly all change into okapis:
IF it was for maybe thousand of ys we could see them changig into ocapis not suddenly though but gradually.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
elongated girrafes neck, being first an epigenetic change, Where did you show this? No, it means that natural selection is what pushes a population in a given morphological direction.
Do you really think that natural selection, which surely works, acts against and not in cocordance with existing phenotype, that is partly a response to epigenetic effect. This last is a fact i think. Edited by zi ko, : No reason given.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Koonin EV, Wolf YI (2009). "Is evolution Darwinian or/and Lamarckian?". Biol Direct 4: 42. doi:10.1186/1745-6150-4-42. PMC 2781790. PMID 19906303. //Is evolution Darwinian or/and Lamarckian? - PMC.
As you can see scientists have quite different ideas from you about evolution.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Can you cite specifics from the paper and how it contradicts what we have been saying? I quote However, various evolutionary phenomena that came to fore in the last few years, seem to fit a more broadly interpreted (quasi)Lamarckian paradigm. The prokaryotic CRISPR-Cas system of defense against mobile elements seems to function via a bona fide Lamarckian mechanism, namely, by integrating small segments of viral or plasmid DNA into specific loci in the host prokaryote genome and then utilizing the respective transcripts to destroy the cognate mobile element DNA (or RNA). A similar principle seems to be employed in the piRNA branch of RNA interference which is involved in defense against transposable elements in the animal germ line. Horizontal gene transfer (HGT), a dominant evolutionary process, at least, in prokaryotes, appears to be a form of (quasi)Lamarckian inheritance. The rate of HGT and the nature of acquired genes depend on the environment of the recipient organism and, in some cases, the transferred genes confer a selective advantage for growth in that environment, meeting the Lamarckian criteria. Various forms of stress-induced mutagenesis are tightly regulated and comprise a universal adaptive response to environmental stress in cellular life forms. Stress-induced mutagenesis can be construed as a quasi-Lamarckian phenomenon because the induced genomic changes, although random, are triggered by environmental factors and are beneficial to the organism. ConclusionBoth Darwinian and Lamarckian modalities of evolution appear to be important, and reflect different aspects of the interaction between populations and the environment.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Nothing in that paper supports your assertions or contradicts anything I wrote. I quote:"However, various evolutionary phenomena that came to fore in the last few years, seem to fit a more broadly interpreted (quasi)Lamarckian paradigm. The prokaryotic CRISPR-Cas system of defense against mobile elements seems to function via a bona fide Lamarckian mechanism, namely, by integrating small segments of viral or plasmid DNA into specific loci in the host prokaryote genome and then utilizing the respective transcripts to destroy the cognate mobile element DNA (or RNA). A similar principle seems to be employed in the piRNA branch of RNA interference which is involved in defense against transposable elements in the animal germ line. Horizontal gene transfer (HGT), a dominant evolutionary process, at least, in prokaryotes, appears to be a form of (quasi)Lamarckian inheritance. The rate of HGT and the nature of acquired genes depend on the environment of the recipient organism and, in some cases, the transferred genes confer a selective advantage for growth in that environment, meeting the Lamarckian criteria. Various forms of stress-induced mutagenesis are tightly regulated and comprise a universal adaptive response to environmental stress in cellular life forms. Stress-induced mutagenesis can be construed as a quasi-Lamarckian phenomenon because the induced genomic changes, although random, are triggered by environmental factors and are beneficial to the organism. Conclusion Both Darwinian and Lamarckian modalities of evolution appear to be important, and reflect different aspects of the interaction between populations and the environment." Aren't they enough?
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Can you cite specifics from the paper and how it contradicts what we have been saying? What are these modalities, and how do they demonstrated guided mutations in eukaryotes? --------------------------------------------------------------------------------//Is evolution Darwinian or/and Lamarckian? - PMC. quote:In the rest of this article we discuss the recent studies of several phenomena that seem to call for resurrection of the Lamarckian scenario of evolution.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Next up, they move on to what they call "quasi-Lamarckian" processes and begin by bumbling a description of stress-induced mutagenesis.... I'd go further: it's not Lamarckian at all. It does not meet their criteria. There is a response to the environment, yes, but the heritable change is strictly random and Darwinian; it's mutation followed by selection. There is no targeting (it does not meet their criteria 2). If we're to consider this "quasi-Lamarckian" then it is not clear that any mutation is not "quasi-Lamarckian" since nearly all mutation are induced by the environment - whether by radiation, free radicals or carcinogenic compounds. Thus allowing stress-induced mutation as Lamarckian renders the concept meaningless.
"There is a response to the environment, yes,... but the heritable change is strictly random and Darwinian;" So you accept there is a mechanism that communicates environment and genome."but the heritable change is strictly random and Darwinian": Coonin accepts the possibility of coexistance of random and guided mechanisms.So what? Moreover there is no evidence of plasmids picking up is random. It is your own assumption. Of course randomness can explain evolution (some aspects of it), but that does not exclude, as there is not any evidence, other explanations as well( e.g guided evolution).
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
There is some merit in the claim that cellular damage can trigger mechanisms that increase HGT.....
Of course bacteria don't know.But environment ,as you are suggesting by your first sentence, can fascilitate HGT (why not and other mechanisms as well ?)
..... The mechanisms that move DNA from one bacteria to another do not read the DNA before taking in the DNA. The bacteria have no idea what the sequence of the plasmids are before it enters the bacteria. Why should we include these other explanations when there is no evidence for them?
Coonin at all have brought quite a lot of evidence, enough to convince themselves and others as well, or at least to make some to rethink about their fixed and uninevidenced ideas.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Curiously, what your conscience can accept or not is totally irrelevant to what actually occurs, and your conscience or opinions are stunningly incapable of altering reality.
It is so strange to me that this type of authoritarian remark, so many times repeated on this forum, in spite of, many times at least by me, questioning about the evidence that supports this authoritative opinion, the responce was very poor, regarding metazoans. One would expect on such crucial matter(random vs guided+random mutations) the amount and quality of such evidence to be overwhelming in the favor of randomness. Nothing of this it happens. Just choosing a suspiciously handy theory and that is all.Instead, again very much authoritatively, it is asked by the 'shaking' opponent to bring the needed evidence. They well know (from their own experience on this matter) this is at present level of science almost impossible. Edited by zi ko, : No reason given.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
The only one making authoritarian remarks is you.
This could be the ultimate brass!Lamarckism had been so unjustly neglected for centuries, and now that serious scientists try with evidence to put it on the right place, you accuse their advocates as being authoritarian! I only asked to discuss their new evidence as an alternative to evolution.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
The current theory, being well established and accepted, does have the "authority" to claim that mutations are random with respect to fitness because that idea has been well tested and supported by the evidence.
Yes, randomness of mutations in relation to fitness is well established and accepted , and it could well be the only explanation for evolution, but it was not well evidenced for the part of metazoans. and it is not falsifiable. What you propose is interesting and worthwhile to debate, but in order for those ideas to gain acceptance you need to bring "extraordinary" evidence.
Mind you, i don't say that guided mutations are necessarily related to fitness. As for the "extraordinary" evidence needed for my ideas, i have to insist again that current theory can work equally perfectly well, without any change, using either the notion of random mutations , or that of guided mutations. So my ideas do not need any further evidence than that offered by current theory.
...the burden of proof is on YOU! Why can't you understand this?????
Can you understand now why i can't understand??? Edited by zi ko, : No reason given.
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zi ko Member (Idle past 3648 days) Posts: 578 Joined: |
Then what are they related to?
We have in front of us the reality of life.This is what they are related to.
So guided mutations are indistinguishable from random mutations? And here you are accusing random mutations of being unfalsifiable. It appears that it is guided mutations that are unfalsifiable.
Random and guided mutations are equally unfalsifiable. Your example of falcification of random mutatations could easily be used to falsify guided mutations as well, unless you could bring reliable works favoring randomness about time needed to have the present life diversity. Edited by zi ko, : No reason given.
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