Notices
Results 1 to 43 of 43

Thread: Evolutionary 'half-step' backwards?

  1. #1 Evolutionary 'half-step' backwards? 
    Forum Senior Booms's Avatar
    Join Date
    Sep 2008
    Location
    The perceptual schematic known as earth
    Posts
    361
    According to conventional evolutionary theory. We evolve basically through a series of random mutations, the beneficial ones remain and slowly evolve through the entire species, while the detrimental ones will, at the very least within a few generations, be removed from the gene pool.


    What I want to know is:
    Can a poor mutation be covered up, but not removed, by a second?

    For example, (extreme, but it makes my point) Lemming develop a cerebral anomaly that causes a huge increase of hormones, compelling them to dive from cliffs.
    Normally, any lemmings with this mutation will quickly be removed from the gene pool. But instead, purely by chance they also develop a thin membrane that acts as a glider, preventing their initial mutation causing death. Meaning the initially poor mutation compelling them to dive from cliffs is not removed, and when the species slowly migrate away from high cliffs, the mutation still exists, and is no longer removed (there are no longer cliffs nearby to leap from)


    I know that, in theory, it could happen. In fact I think such an occurrence happened in humans.
    What I really want to know, is if anyone knows of any proven instances where this has happened, where one detrimental evolution has survived through a second?


    It's not how many questions you ask, but the answers you get - Booms

    This is the Acadamy of Science! we don't need to 'prove' anything!
    Reply With Quote  
     

  2.  
     

  3. #2  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    I am puzzled by your apparent absolute identification of mutations as either harmful or beneficial. In a flat environment the drive to jump of cliffs would be a neutral mutation and the development of gliding membrane would be a harmful one, since energy would be wasted producing a useless piece of flesh.

    Since this point is fundamental and you seem to have missed it, I'm not sure your question actually has any meaning.


    Reply With Quote  
     

  4. #3  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,795
    Lemmings don't really dive off cliffs.

    http://en.wikipedia.org/wiki/Lemming...misconceptions
    Reply With Quote  
     

  5. #4  
    Forum Freshman
    Join Date
    Feb 2011
    Posts
    58
    Quote Originally Posted by Ophiolite
    I am puzzled by your apparent absolute identification of mutations as either harmful or beneficial. In a flat environment the drive to jump of cliffs would be a neutral mutation and the development of gliding membrane would be a harmful one, since energy would be wasted producing a useless piece of flesh.

    Since this point is fundamental and you seem to have missed it, I'm not sure your question actually has any meaning.

    Forgive me for challenging you. I am a novice with this subject.

    ''Mutation can result in several different types of change in DNA sequences; these can have no effect, alter the product of a gene, or prevent the gene from functioning properly or completely.''


    Genetics speaks of mutations as either harmful or beneficial.
    A harmful mutation is a mutation that decreases the fitness of the organism.
    A beneficial mutation is a mutation that increases fitness of the organism, or which promotes traits that are desirable.
    Reply With Quote  
     

  6. #5  
    Veracity Vigilante inow's Avatar
    Join Date
    Oct 2009
    Location
    Austin, TX
    Posts
    3,499
    But some mutations are just sorta neutral, and simply hang out in the background not doing much of anything... zero impact on the fitness of the organism.
    Reply With Quote  
     

  7. #6  
    Forum Cosmic Wizard i_feel_tiredsleepy's Avatar
    Join Date
    Mar 2008
    Location
    Montreal
    Posts
    2,256
    Quote Originally Posted by Hippocampus


    Forgive me for challenging you. I am a novice with this subject.

    ''Mutation can result in several different types of change in DNA sequences; these can have no effect, alter the product of a gene, or prevent the gene from functioning properly or completely.''


    Genetics speaks of mutations as either harmful or beneficial.
    A harmful mutation is a mutation that decreases the fitness of the organism.
    A beneficial mutation is a mutation that increases fitness of the organism, or which promotes traits that are desirable.
    As Ophi said, whether a mutation improves or decreases fitness depends on what the selective pressures are. A mutation is not objectively harmful or beneficial out of context, apart from perhaps mutations that produce non-viable organisms. And this becomes even more complicated when we start considering things like kin-selection.
    "I almost went to bed
    without remembering
    the four white violets
    I put in the button-hole
    of your green sweater

    and how i kissed you then
    and you kissed me
    shy as though I'd
    never been your lover "
    - Leonard Cohen
    Reply With Quote  
     

  8. #7  
    Moderator Moderator TheBiologista's Avatar
    Join Date
    Aug 2008
    Posts
    2,564
    Quote Originally Posted by Hippocampus
    Genetics speaks of mutations as either harmful or beneficial.
    They are, but with some caveats. One is that harm and benefit are extremes at either end of a continuum. Another is that none of the extremes or various shades of grey on that continuum is an absolute- all are subject to changes in context that can turn benefit into harm or vice versa.
    Reply With Quote  
     

  9. #8  
    Forum Senior questor's Avatar
    Join Date
    Jan 2011
    Posts
    385
    Death is the chooser, as always, sifting the rest from the best.
    Reply With Quote  
     

  10. #9  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    Quote Originally Posted by Hippocampus
    Forgive me for challenging you. I am a novice with this subject.
    Challenge away. We are all ultimately novices.

    Quote Originally Posted by Hippocampus
    Genetics speaks of mutations as either harmful or beneficial.
    A harmful mutation is a mutation that decreases the fitness of the organism.
    A beneficial mutation is a mutation that increases fitness of the organism, or which promotes traits that are desirable.
    These statements are incomplete. Their incompleteness redners them seriously misleading in understanding genetics and evolution. Here they are completed.

    A harmful mutation is a mutation that decreases the fitness of the organism in a specific environment. A beneficial mutation is a mutation that increases fitness of the organism in a specific environment, or which promotes traits that are desirable in a specific environment.

    Fitness is not an absolute, but a relative. Moreover it is a relative in specific contexts, not necessarily all contexts.

    Does this make sense to you?
    Reply With Quote  
     

  11. #10  
    Forum Freshman
    Join Date
    Feb 2011
    Posts
    58
    Quote Originally Posted by Ophiolite
    Quote Originally Posted by Hippocampus
    Forgive me for challenging you. I am a novice with this subject.
    Challenge away. We are all ultimately novices.

    Quote Originally Posted by Hippocampus
    Genetics speaks of mutations as either harmful or beneficial.
    A harmful mutation is a mutation that decreases the fitness of the organism.
    A beneficial mutation is a mutation that increases fitness of the organism, or which promotes traits that are desirable.
    These statements are incomplete. Their incompleteness redners them seriously misleading in understanding genetics and evolution. Here they are completed.

    A harmful mutation is a mutation that decreases the fitness of the organism in a specific environment. A beneficial mutation is a mutation that increases fitness of the organism in a specific environment, or which promotes traits that are desirable in a specific environment.

    Fitness is not an absolute, but a relative. Moreover it is a relative in specific contexts, not necessarily all contexts.

    Does this make sense to you?
    Sure, natural selection will make its choices.
    Reply With Quote  
     

  12. #11  
    Forum Freshman
    Join Date
    Feb 2011
    Posts
    58
    I am puzzled by your apparent absolute identification of mutations as either harmful or beneficial. In a flat environment the drive to jump of cliffs would be a neutral mutation and the development of gliding membrane would be a harmful one, since energy would be wasted producing a useless piece of flesh.

    Since this point is fundamental and you seem to have missed it, I'm not sure your question actually has any meaning.
    However, his question makes sense .

    Can a poor mutation be covered up, but not removed, by a second?

    I believe that it happens all the time for example in the dormant DNA.
    Reply With Quote  
     

  13. #12  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    According to Neo-Darwinism synthesis, evolution is a blend of a chance and selection. These days, very few scientists argue against biological evolution or the role of natural selection, but there are few who don't agree that random mutations are `creative enough' to provide material for this selection. This argument is a central to the opposition to Neo-Darwinism, and is rooted in the theory of probability that prohibits the single point mutation to create complex adaptive features. The attempts to defend the mechanism of random mutation often utilize computer-based algorithms in order to demonstrate the power of cumulative selection. However Dawkins is careful to point out that the cumulative selection is strictly a model of artificial selection, not natural one. More sophisticated attempt to defend the mechanism of random mutation was published in Nature, May 8, 2003 `The Evolutionary Origin of Complex Features'). This article was widely reported to shed light on the biggest unanswered questions of biological evolution.
    To demonstrate that complex systems evolve from simpler precursors, the authors set up small rewards for simpler operations and bigger rewards for ones that are more complex and this way provide an incentive to evolve through a gradual process. However, the authors admitted `... the complex feature never evolved when simpler functions were not rewarded ... .' This result rather confirms the argument of the opponent to Neo-Darwinism.
    Unfortunately, the discussions of biological evolution are tainted by ideology and there is unwillingness on part of the scientific community openly acknowledge the gaps in this theory. The irony is that scientists, have no problem to admit that most of the life-related phenomena are still far from being understood. Why should the mechanisms of biological evolution be an exception?
    Reply With Quote  
     

  14. #13  
    Moderator Moderator TheBiologista's Avatar
    Join Date
    Aug 2008
    Posts
    2,564
    Quote Originally Posted by miosim
    According to Neo-Darwinism synthesis, evolution is a blend of a chance and selection. These days, very few scientists argue against biological evolution or the role of natural selection, but there are few who don't agree that random mutations are `creative enough' to provide material for this selection. This argument is a central to the opposition to Neo-Darwinism, and is rooted in the theory of probability that prohibits the single point mutation to create complex adaptive features. The attempts to defend the mechanism of random mutation often utilize computer-based algorithms in order to demonstrate the power of cumulative selection. However Dawkins is careful to point out that the cumulative selection is strictly a model of artificial selection, not natural one. More sophisticated attempt to defend the mechanism of random mutation was published in Nature, May 8, 2003 `The Evolutionary Origin of Complex Features'). This article was widely reported to shed light on the biggest unanswered questions of biological evolution.
    To demonstrate that complex systems evolve from simpler precursors, the authors set up small rewards for simpler operations and bigger rewards for ones that are more complex and this way provide an incentive to evolve through a gradual process. However, the authors admitted `... the complex feature never evolved when simpler functions were not rewarded ... .' This result rather confirms the argument of the opponent to Neo-Darwinism.
    Unfortunately, the discussions of biological evolution are tainted by ideology and there is unwillingness on part of the scientific community openly acknowledge the gaps in this theory. The irony is that scientists, have no problem to admit that most of the life-related phenomena are still far from being understood. Why should the mechanisms of biological evolution be an exception?
    Because it's really much better understood than you realise. The gaps as primarily in our knowledge of the phylogeny, the output of the theory, not in the theory itself.
    Reply With Quote  
     

  15. #14  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    I don’t want spend time arguing about this matter. I just had discussion on Amazon forum with people having similar views. If you are interested, you may follow the result of that discussion at:

    http://www.amazon.com/tag/evolution/...x1E3QCYP64DXH4

    Regards,

    Mark
    Reply With Quote  
     

  16. #15  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    My post was indented for those who are interested in science and have an open mind. Yours post is just an invitation to participate in the ideological war between evolutionists and creationists. As I am concerned, both of these categories more concern about their beliefs than about a truth.
    Reply With Quote  
     

  17. #16  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,840
    There are, in fact, many genetic features that go both ways. For example : humans have a gene that acts in a pregnant mother to limit the nutrients the fetus receives. Clearly this is for the benefit of the mother, who would be weakened if nutrient removal was excessive.

    However, at exactly the same time, a gene in the fetus is active which causes the release of chemicals to promote the release of nutrients from the mother.

    Two genes with opposite actions - one neutralising the other. In the end a balance is achieved.

    Biochemically, this is common, and is part of the body's control mechanisms, where one gene promotes a chemical function, and another acts to stop it.

    It is also worth noting that the majority of mutations in fact are so trivial that they cannot really be called either beneficial or harmful. Since there is little or no selection pressure to eliminate these, they accumulate in the gene pool. The humasn genome contains vast numbers of such mutated genes.

    In evolutionary terms, these are considered to have an effect when the environment changes. A gene that is kinda impotent in one environment may become beneficial when things change. If that happens, the gene frequency increases through natural selection, and evolution is in action.
    Reply With Quote  
     

  18. #17  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    As I am concerned, there is only one challenge to Neo-Darwinism; the role of random mutation to create complex adaptive mechanisms (Irreducible Complexity).

    By the way, the original Darwinism doesn’t have this problem, because Darwin’s graduate changes are meant larger in scale and relevant to survival.

    The challenge of Irreducible Complexity is formulated in terms of theory of probability, stating that emergence of complex adaptation due to random mutation is highly improbable proposition. Therefore the respond to this challenge should be formulated in the same terms of mathematical probability, but not in terms of rhetorical arguments.
    Reply With Quote  
     

  19. #18  
    Forum Cosmic Wizard i_feel_tiredsleepy's Avatar
    Join Date
    Mar 2008
    Location
    Montreal
    Posts
    2,256
    Quote Originally Posted by miosim
    As I am concerned, there is only one challenge to Neo-Darwinism; the role of random mutation to create complex adaptive mechanisms (Irreducible Complexity).

    By the way, the original Darwinism doesn’t have this problem, because Darwin’s graduate changes are meant larger in scale and relevant to survival.

    The challenge of Irreducible Complexity is formulated in terms of theory of probability, stating that emergence of complex adaptation due to random mutation is highly improbable proposition. Therefore the respond to this challenge should be formulated in the same terms of mathematical probability, but not in terms of rhetorical arguments.
    No it's not, it's formulated in terms of an argument from ignorance. The weakness of which has been shown by Behe's chosen Irreducibly Complex structures, like the flagella, later being shown to have indeed have had simpler precursors.
    "I almost went to bed
    without remembering
    the four white violets
    I put in the button-hole
    of your green sweater

    and how i kissed you then
    and you kissed me
    shy as though I'd
    never been your lover "
    - Leonard Cohen
    Reply With Quote  
     

  20. #19  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    This argument is rooted in the theory of probability that prohibits the single point mutation to create complex adaptive features. Behe just “repackaged” it in the non-mathematical terms of “Irreducible Complexity”.

    The attempts to defend the mechanism of random mutation often utilize computer-based algorithms in order to demonstrate the power of cumulative selection (see http://en.wikipedia.org/wiki/Weasel_program). However Dawkins is careful to point out that the cumulative selection is strictly a model of artificial selection, not natural one. To apply the mechanism of cumulative selection to natural evolution we need to assume that environment represent the “appropriate fitness function” that, as target in Weasel program, leads individual random mutations to the complex adaptations. The main argument of Behe is that it is impossible to define the “appropriate fitness function” that would provide gradual evolution. Dawkins’s counterargument is that regardless that we can’t reproduce these conditions now, it doesn’t mean they couldn’t exist millions or billions years ago. Dawkins expects that sooner or later the “appropriate fitness function” will be found and he has tried to demonstrate that this is not an impossible proposition.

    I had two discussions about these issues; first at http://www.antievolution.org few years ago and the second recently at http://www.amazon.com/tag/evolution/forum. I think that I made my point clear enough to calm down my opponents, but they still couldn’t openly admit the problem with mechanism of random mutations. Apparently, their prime concern wasn’t about science, but about do not providing more ammunition to creationists. This I call ignorance.
    Reply With Quote  
     

  21. #20  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55° N, 3° W
    Posts
    1,085
    miosim, there is no genuine argument rooted in probabilities. To create such an argument you have to first create a fatally flawed model of evolution - basically what amounts to a strawman. That you keep referring to single point mutations is evidence enough that you still have a great deal to learn about how evolution works.
    Reply With Quote  
     

  22. #21  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    Quote Originally Posted by Zwirko
    miosim, there is no genuine argument rooted in probabilities. To create such an argument you have to first create a fatally flawed model of evolution - basically what amounts to a strawman. That you keep referring to single point mutations is evidence enough that you still have a great deal to learn about how evolution works.
    Indeed, you probably know much more about the theory evolution; this isn’t a focus of my research.

    I personally have no problem with Darwinian theory of evolution, but I believe that the foundation of Neo-Darwinism is built on the shaky ground of the mechanism of single point mutations that wasn’t demonstrated yet. This mechanism is also causes the significant concern, because it contradicts with the basic statistical analysis.
    At the same time a gap in understanding of this mechanism doesn’t negate evolution yet.

    As I understand, in science the burden of proof is on those who put forward the theory. Therefore the burden to prove the theory of evolution is on evolutionists, but not on ID supporters to disprove it.

    Normally for the scientific theory to be accepted it should demonstrate both; its feasibility and to be supported by experiment or data. The mechanism of gradual changes based on random mutations doesn't comply with either of those requirements. The ID supported just point to this fact and ridicule ‘devoted' evolutionists for ignorance.
    Reply With Quote  
     

  23. #22  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    Quote Originally Posted by Zwirko
    miosim, there is no genuine argument rooted in probabilities.
    It is genuine enough if authors of article “The Evolutionary Origin of Complex Features” published in NATURE, called it “A long-standing challenge…”:

    http://myxo.css.msu.edu/lenski/pdf/2...%20et%20al.pdf

    “A long-standing challenge to evolutionary theory has been whether it can explain the origin of complex organismal features…”
    Reply With Quote  
     

  24. #23  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55° N, 3° W
    Posts
    1,085
    It has always been theoretically challenging that large scale evolutionary change takes place via multiple, incremental small mutations.. A challenge to understand and uncover the mechanisms at work, not a challenge to overcome a statistical nightmare that does not in fact exist. Where in the referenced article do they say that evolution of complex features is improbable?

    Did the conclusion of the paper escape you? : "These findings show how complex functions can originate by random mutation and natural selection." or "... the complex function evolved with a high probability..."
    Reply With Quote  
     

  25. #24  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    Quote Originally Posted by Zwirko
    ... Where in the referenced article do they say that evolution of complex features is improbable? ...
    ... Did the conclusion of the paper escape you? : "These findings show how complex functions can originate by random mutation and natural selection." or "... the complex function evolved with a high probability..."

    To demonstrate that complex systems evolve from simpler precursors authors set up small rewards for simpler operations and bigger rewards for more complex ones and this way provide an “incentive” to evolve through the gradual process. However, when the researchers took away rewards for simpler operations, “digital organisms” never found a final solution.

    To understand this paper it need to be read carefully and between lines, because authors try to hide their failure to address a “long-standing challenge to evolutionary theory”. The original (non-disclosed) goal of this study was the attempt to demonstrate that “digital organisms” able to find a final solution without rewards for simpler operations.
    Reply With Quote  
     

  26. #25  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55° N, 3° W
    Posts
    1,085
    I don't believe you have understood the paper; a careful reading would seem to be very damaging to your views.


    You've yet to demonstrate the statistical problems that evolutionary biology must come to terms with. Care to provide the evidence? Also, I'd like to see evidence that shows that modern evolutionary biology rests upon a foundation of point mutations.
    Reply With Quote  
     

  27. #26 Introduction with a question 
    New Member
    Join Date
    Feb 2011
    Posts
    1
    Hello Everyone ! I want to ask a question that "can a man survive after a stroke of brain tumor "
    Diet Ebooks
    Reply With Quote  
     

  28. #27  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    You've yet to demonstrate the statistical problems that evolutionary biology must come to terms with. Care to provide the evidence?
    In the past I spent some time studying this paper and then shared my findings with the folks from antievolution.org I was disputing with. These folks weren’t very friendly to me, but at least they were knowledgeable in the area of evolution algorithm (especially Wesley R. Elsberry) to fully understand my arguments. You can check how they put up with my presentation. Look for my post dated Feb. 05 2008,23:24 at:

    http://www.antievolution.org/cgi-bin...t=5199;st=1410

    Also, I'd like to see evidence that shows that modern evolutionary biology rests upon a foundation of point mutations
    I agree with you that the modern evolutionary biology doesn’t rest upon a foundation of point mutations; Neo-Darwinism just pretends that it has a solid foundation.
    That means that if tomorrow we will reject the point mutations paradigm, it wouldn’t affect at all our understanding of evolutionary biology.
    Reply With Quote  
     

  29. #28  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55° N, 3° W
    Posts
    1,085
    You appear to be discussing computer programs that attempt to model evolution, nothing more. As models of evolution they are limited in their usefulness - and certainly don't warrant the grand claims such as you have made.

    Don't misunderstand me - point mutations are important. I wanted to impress upon you that evolution has a far bigger and varied arsenal at its disposal than solely this particular class of mutation. Likewise, there is more going on than natural selection.
    Reply With Quote  
     

  30. #29  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    Quote Originally Posted by Zwirko
    You appear to be discussing computer programs that attempt to model evolution, nothing more. As models of evolution they are limited in their usefulness - and certainly don't warrant the grand claims such as you have made.

    Let’s not take the importance of this theoretical model lightly, otherwise we may open a can of worms.
    I may agree that specific mechanisms of gradual evolution will not change our general perception of biological evolution. However the same is true for quantum mechanics where the application of orthodox quantum chemistry does not lead to the undoubtedly correct description of chemical phenomena. For a great majority of applied sciences, the atom is ground zero, the foundation of all other knowledge, and therefore the exploration below this level has no practical significance for our knowledge of chemistry and biology.

    Because of that, would quantum theory have limited usefulness? Would revealing misleading claims about the foundation of quantum mechanics warrant the grand claims?
    Reply With Quote  
     

  31. #30  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55° N, 3° W
    Posts
    1,085
    Bad analogy. There are simply too many important variables in operation over such long time scales that are not included in these models. Neither do the models accurately portray those aspects of biology that have been programmed into them. Models are theoretically interesting and can even lead to new understanding. They don't demonstrate or support the claim you have made, not even remotely.

    As well as such in silico studies with digital organisms, we can also study real, actual living organisms. A third possibility exists: continuous, directed in vitro molecular evolution. What are your opinions on the latter?
    Reply With Quote  
     

  32. #31  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    ...There are simply too many important variables in operation over such long time scales that are not included in these models. Neither do the models accurately portray those aspects of biology that have been programmed into them...
    This model isn’t about replicating the specific aspects of biological evolution, but about addressing a long-standing challenge to evolutionary theory; to demonstrate the feasibility of the single point mutation mechanism—which turned to be improbable (of cause if we pay attention to details).

    Models are theoretically interesting and can even lead to new understanding. They don't demonstrate or support the claim you have made, not even remotely.
    The actual result of this study proves my claim that without rewards for simpler operations, “digital organisms” couldn’t evolve. However authors of this paper mask this result and mislead public by claiming that they demonstrated the evolutionary emergence of complex features. Unfortunately, occasionally carrier scientists make deceiving claims, especially in the ideologically charged area of evolution theory.

    As well as such in silico studies with digital organisms, we can also study real, actual living organisms. A third possibility exists: continuous, directed in vitro molecular evolution. What are your opinions on the latter?
    Do you mean “directed” (vs. random) molecular evolution?
    Reply With Quote  
     

  33. #32  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55° N, 3° W
    Posts
    1,085
    I know what the model is about. I'm trying to point out to you that you can't claim that an aspect of evolution is impossible based on the output of a model - especially when there is direct observational evidence (in the real world) contrary to the proof that you say the model makes (you only need to read any of Behe's recent work to realise this). As I said previously, there is no long standing challenge "to demonstrate the feasibility of the single point mutation mechanism".

    Since it is the reward/no reward situation that you appear to find troublesome, perhaps you could explain what you think "reward" means in the context of this model and why it presents a problem?

    I'd also very much appreciate it if you could just drop the whole conspiracy theory stuff, the accusations of deceit and lies and the silly "ideology" angle you keep returning to. It just antagonises people and weakens your status as someone with a point worth taking seriously. Evolutionary biology is not ideologically charged.


    Do you mean “directed” (vs. random) molecular evolution?
    No. I was referring to a technique called "directed in vitro evolution".
    Reply With Quote  
     

  34. #33  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    As I said previously, there is no long standing challenge "to demonstrate the feasibility of the single point mutation mechanism".
    So what “A long-standing challenge to evolutionary theory “ is the authors in Nature magazine refer to?


    I'd also very much appreciate it if you could just drop the whole conspiracy theory stuff, the accusations of deceit and lies and the silly "ideology" angle you keep returning to. It just antagonises people and weakens your status as someone with a point worth taking seriously. Evolutionary biology is not ideologically charged.
    I also prefer to focus on scientific discussion and don’t “spill” it into issue of ethics, which by the way, I have a strong feeling about. This issue deserves a special conversation.

    Regarding, the topic of role of random mutations in biological evolution I tried to make my point and probably wouldn’t able to contribute more for this discussion. Instead I would like to focus on the discussion I recently started at Scientist Solutions forum: Home »
    Forums » General » Forum Suggestions » Philosophy of life science:

    http://www.scientistsolutions.com/t1...e+science.html

    were I discuss my essay “The Simplicity of Complex Systems: The Inquiry into the Nature of Life, Mind, and Death Phenomena”,

    This is a very controversial concept that violates more than one scientific paradigm.
    If you choose to join this discussion I would appreciate your constructive criticism.

    Thank you,
    Mark Iosim
    Reply With Quote  
     

  35. #34  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55° N, 3° W
    Posts
    1,085
    The challenging task is to provide a detailed step-by-step account of how incremental changes over time lead to the development of complex features. This is problematical for many reasons, largely due to the evidence continually being erased from history.
    The challenge is not "to demonstrate the feasibility of the single point mutation mechanism". Can you see the difference?
    Reply With Quote  
     

  36. #35  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    I see your point. However I interpret this "challenge" in context of Richard E. Lenski (who is one of coauthor of the paper in Nature) research “Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli”.
    http://www.pnas.org/content/105/23/7899.full

    This study is all about random mutations and “… a profound tension between random and deterministic processes ...”.

    I found very helpful for understanding the Lenski paper in Nature by reading the article in the Discovery magazine “Testing Darwin” http://discovermagazine.com/2005/feb/cover

    “ …On a trip to Michigan State, Adami met microbiologist Richard Lenski, who studies the evolution of bacteria. Adami later sent Lenski a copy of the Avida software so he could try it out for himself. On a Friday, Lenski loaded the program into his computer and began to create digital worlds. By Monday he was tempted to shut down his laboratory and dedicate himself to Avida. “It just had the smell of life,” says Lenski …”

    Finally, the interpretation of “A long-standing challenge to evolutionary theory…” isn’t the most important issue for me and therefore I wouldn’t spend time to defend this point .
    Reply With Quote  
     

  37. #36  
    Forum Cosmic Wizard i_feel_tiredsleepy's Avatar
    Join Date
    Mar 2008
    Location
    Montreal
    Posts
    2,256
    Quote Originally Posted by miosim
    I see your point. However I interpret this "challenge" in context of Richard E. Lenski (who is one of coauthor of the paper in Nature) research “Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli”.
    http://www.pnas.org/content/105/23/7899.full

    This study is all about random mutations and “… a profound tension between random and deterministic processes ...”.
    But that doesn't contradict Zwirko at all...

    The "profound tension" is between randomness of mutations and the deterministic qualities of natural selection. The article is also concerned with the implications of limited possibilities created by evolutionary history. However, none of this supports the positions you've expressed in this thread.
    "I almost went to bed
    without remembering
    the four white violets
    I put in the button-hole
    of your green sweater

    and how i kissed you then
    and you kissed me
    shy as though I'd
    never been your lover "
    - Leonard Cohen
    Reply With Quote  
     

  38. #37  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    The "profound tension" is between randomness of mutations and the deterministic qualities of natural selection. The article is also concerned with the implications of limited possibilities created by evolutionary history. However, none of this supports the positions you've expressed in this thread
    (1) - from paper in Nature
    “A long-standing challenge to evolutionary theory has been whether it can explain the origin of COMPLEX ORGANISMAL FEATURES. …:

    (2) - from “Testing Darwin”
    “What we show is that there are IRREDUCIBLY COMPLEX THINGS and they can evolve”

    (3) –from http://en.wikipedia.org/wiki/Irreducible_complexity
    “Irreducible complexity (IC) is an argument by proponents of intelligent design that certain biological systems are too complex to have evolved from simpler or "less complete" predecessors, through natural selection acting upon a series of advantageous naturally-occurring, CHANCE MUTATIONS."

    I wonder if by connecting dots between (1), (2) and (3) you can trace “A long-standing challenge to evolutionary theory” to CHANCE MUTATIONS.


    One more thing:
    from “Testing Darwin”
    “When the Avida team published their first results on the evolution of complexity in 2003, … (this) work hit a nerve in the antievolution movement and hit it hard …”

    Do you realize that the result of this study (complex feature never evolved when simpler functions were not rewarded) fully supports the claim of creationists that without rewarding single point mutation complex features can’t evolve
    Reply With Quote  
     

  39. #38  
    Moderator Moderator TheBiologista's Avatar
    Join Date
    Aug 2008
    Posts
    2,564
    Quote Originally Posted by miosim
    The "profound tension" is between randomness of mutations and the deterministic qualities of natural selection. The article is also concerned with the implications of limited possibilities created by evolutionary history. However, none of this supports the positions you've expressed in this thread
    (1) - from paper in Nature
    “A long-standing challenge to evolutionary theory has been whether it can explain the origin of COMPLEX ORGANISMAL FEATURES. …:

    (2) - from “Testing Darwin”
    “What we show is that there are IRREDUCIBLY COMPLEX THINGS and they can evolve”

    (3) –from http://en.wikipedia.org/wiki/Irreducible_complexity
    “Irreducible complexity (IC) is an argument by proponents of intelligent design that certain biological systems are too complex to have evolved from simpler or "less complete" predecessors, through natural selection acting upon a series of advantageous naturally-occurring, CHANCE MUTATIONS."

    I wonder if by connecting dots between (1), (2) and (3) you can trace “A long-standing challenge to evolutionary theory” to CHANCE MUTATIONS.


    One more thing:
    from “Testing Darwin”
    “When the Avida team published their first results on the evolution of complexity in 2003, … (this) work hit a nerve in the antievolution movement and hit it hard …”

    Do you realize that the result of this study (complex feature never evolved when simpler functions were not rewarded) fully supports the claim of creationists that without rewarding single point mutation complex features can’t evolve
    Congratulations, you just joined the dots, and the dots spell 'pseudoscience'.
    Reply With Quote  
     

  40. #39  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    TheBiologista,

    You made a very strong argument
    Reply With Quote  
     

  41. #40  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55° N, 3° W
    Posts
    1,085
    A long-standing challenge to evolutionary theory has been whether it can explain the origin of COMPLEX ORGANISMAL FEATURES
    You're still misunderstanding what the authors of the Lenski et al paper meant by explaining a "long standing challenge". It's nothing all to do with there being some doubt about the role of mutations in the evolution of complexity. That is the most fundamental aspect of evolutionary biology, after all. Think about the data that Avida generates and the evolutionary narrative it allows one to construct. Compare that with the narrative that can be constructed for the evolution of the HOX genes and you might come to appreciate the point that Lenski et al were making here. It's not what you seem to think.

    Do you realize that the result of this study (complex feature never evolved when simpler functions were not rewarded) fully supports the claim of creationists that without rewarding single point mutation complex features can’t evolve
    There is no problem here. Can you explain where you see one? That mutations not under selection don't yield complex features is hardly surprising, is it? Complex systems built by co-opting simpler function have to evolve this way, surely? It's also interesting that the no reward populations generate huge diversity - just might come in handy when new selective pressures are introduced. Like before, you appear to be having an issue with what is really a rather fundamental aspect of biology.
    Reply With Quote  
     

  42. #41  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    You're still misunderstanding what the authors of the Lenski et al paper meant by explaining a "long standing challenge". It's nothing all to do with there being some doubt about the role of mutations in the evolution of complexity. That is the most fundamental aspect of evolutionary biology, after all.
    Maybe this would be helpful. Below is the first and the last sentence from the Abstract from paper in Nature
    “A long-standing challenge to evolutionary theory has been whether it can explain the origin of complex organismal features...
    … These findings show how complex functions can originate by random mutation and natural selection.”
    Is this indicate that “A long-standing challenge…” refers to random mutations?

    Code:
    Think about the data that Avida generates and the evolutionary narrative it allows one to construct. Compare that with the narrative that can be constructed for the evolution of the HOX genes and you might come to appreciate the point that Lenski et al were making here. It's not what you seem to think.
    Regarding HOX genes, I accept the narrative as an illustration of how random mutation may lead to large scale functional changes. However I would be careful to use this example as an indirect evidence, because these genes apparently act as the triggers for developmental gene hierarchies.
    Many non specific factors, like temperature, radiation, organic and inorganic compounds, may also affect the regulation of large networks of genes producing large scale development changes.

    Regarding Avida, I can’t accept its narrative. This is the “mathematical model” that suppose to address probability concern (repackaged by creationists as Irreducible Complexity) and I expect mathematically supported claim that emergence of complex function is probable. Instead I have to extract relevant information by reading this paper in between the lines. For example:
    “…The organism would obtain no reward if any of the 32 bits in the string were incorrect…”
    That means the organism is rewarded not for a single point mutation, but only if all 32 mutations forms meaningful pattern. This seams to overturn Irreducible Complexity argument. However for this pattern to evolve computer need to sort 2e+32 = 4294967296 combination that is very possible scenario.
    At the same time in Dawkins’ Weasel program that exemplifies evolutionary changes computer need to try 27e+28 = 1.1972515182562019788602740026717e+40 combinations that apparently isn’t probable at all.
    Apparently dealing with mathematicall concepts we shouldn’t’ rely on narrative.
    Reply With Quote  
     

  43. #42  
    Forum Professor Zwirko's Avatar
    Join Date
    Sep 2008
    Location
    55° N, 3° W
    Posts
    1,085
    miosim, I'm giving up. I've tried - really I have - to help you understand a rather uncomplicated sentence found within an abstract. Each time you respond, your confusion seems all the worse. I fear I am not helping matters. You've totally missed the point about HOX genes versus the gigabytes of generated Avida output - again, this is probably my fault.

    I don't think you have a firm grasp of evolutionary principles or have really gotten to grips with this paper; no insult intended. I've lost the will to continue further and can only wish you good luck with whatever it is you are trying to achieve.
    Reply With Quote  
     

  44. #43  
    Forum Freshman
    Join Date
    Feb 2011
    Location
    USA
    Posts
    17
    Sorry for frustration and thank you for your efforts
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •