Validity of Micro/macro-evolution idea

Discussion in 'Biology & Genetics' started by RoyLennigan, Apr 6, 2007.

  1. RoyLennigan Registered Senior Member

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    From the 'Evolution - True or False' thread:

    I said:
    To which Saquist replied:
    So I put forth the following questions for discussion in a fresh thread:
    What is it about the nature of DNA that causes us to seperate the idea into the mutually exclusive macro and micro evolutions? And is micro evolution all we have been able to observe?

    To Saquist exclusively (though anyone may answer, obviously):
    What is it you have discovered about the nature of DNA and life to cause you to come to the conclusion so certainly that it contradicts basic ideologies of evolution?

    Also, I am interested in what a biblical perspective has to say on the matter.

    I would greatly appreciate it if you took some time to get your thoughts and evidence ready in a clear and concise manner and post your opinion in more of an essay-like form. This is to get your full thoughts out for uninhibited digestion, making it easier to understand. I would rather read a book than staccato remarks.
     
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  3. river-wind Valued Senior Member

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    The terms Macro and Micro evolution were first coined in the 1930s by a guy named Theodosius Dobzhansky when he was helping to devise the idea of modern evolutionary synthesis.

    Having studied under a man who openly supported the idea that change in a population was driven by an unseen force toward a perfect goal, it is not surprising that he sought to form a division between changes in a local population and those of overall species - to suggest that a species, on its way toward perfection, had any need to branch out into different versions of itself, would be absurd.

    Over the following decades, the terms largely disappeared from evolutionary discussion, as the only apparent difference between the variation within a population and the act of speciation was that of degree. No artificial delineation was needed, as the ramp from "micro" to "macro" was nearly even.

    After Gould’s suggestion of punctuated equilibrium (rapid changes in species when faced with drastic environmental shifts), and progress in the field of mathematical chaos theory, the terms have gain a minor amount of traction again. The changes within a population appear to accumulate over time until a tipping point – of accumulated changes, such as with African Cichlid fish, or of geographic separation, as in Darwin’s finches – can lead to a sudden shift toward a divergent population and subsequent speciation.

    (Anyone interested in this idea should try the Button Experiment suggested by Stuart Kauffman (http://complexity.orcon.net.nz/tippingpoint.html) – lay out 50 buttons on the table, and then start tying them together one at a time at random; counting the number of multiple connections made.
    As groups of buttons start accumulating, there is a point at which groups of buttons start connecting to each other, and the average group sizes suddenly jump with the addition of a single connection or two – the change has been prepared for, and a small modification can yield significant results.)


    However, Micro and Macro evolution are still terms largely left alone by modern evolutionists, simply because there is very little evidence (that I’m aware of) that suggests that the driving forces behind changes within a population (random mutation, heredity, natural selection) are any different than those at work at a species level. The terms appear to be completely artificial, but unlike the artificial divisions used during the classification process, they do not appear to aid us in understanding the natural world.


    The major use of the terms today is found in attempts to debunk evolution by religious factions – they have attached to the idea of a difference between genetic shift and speciation as a scientific loophole; they can take all of the evidence in support of evolution, and simply dump it into the microevolution heading. Ignoring that macroevolution is thought to be driven by the same forces, and as such evidence for one is evidence for the other, they demand proof of macroevolution, and then take all such evidence and call it evidence in support of micro-evolution.


    At this point, the difference and the terms should be wiped from the collective minds of evolutionists and creationists alike – it does not appear to be a useful dichotomy in light of the current empirical evidence that we have. The driving forces behind evolution do not change as a group moves farther away from its parent species genetically, and there does not appear to be a perfect goal to which all species slowly move.
     
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  5. Ophiolite Valued Senior Member

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    I think I shall take issue with you on this River Wind. I believe the jury is still out on whether macro-evolution is just micro-evolution writ large, or contains, at least in part, some different mechanisms.

    If speciation events occur, as posited by Darwin, through the slow gradual accumulation of mutations, then micro and macro are identical.

    If speciation events always occur by, for example, the accumulation and dissemination of recessive mutations within a population until they reach sufficient density (probably within a small, isolated sub-community) that they may in an instant express themselves, thus creating the new species, then micro and macro are much the same, but not exactly the same.

    If mutations to certain regulatory genes induce a sudden large scale change, perhaps even sufficient to create, in an instant, a new genera, or even higher taxanomic grouping, [and this is certainly plausible as Kauffman's work would support] then we must retain the two terms.

    Of course all of this is only half the topic, I think, and I apologise to Roy if I have deviated from the purpose of his thread. In that regard I cannot see any conflict at all between the Bible and evolution.
    Only a literal interpretation of the Bible presents difficulties. Given the liking of the Hebrews for metaphor, it seems almost sacriligeous to doubt that their writings, whether or not inspired by God, were not deeply imbued with poetic interpretations of their origins. When read in that light evolution sits very comfortably within any, and I suspect all, parts of the Bible.
     
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  7. RoyLennigan Registered Senior Member

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    This is what I was thinking. I am more apt to see a conceptual dichotomy such as this and interpret it as just another arbitrary line drawn by the human mind. It seems to me that there is no reason for the forces causing small changes to prevent an accumulation of those small changes, therefore causing large change eventually. Whether these larger changes occur gradually, or like the straw that broke the camel's back, I am not so sure. But I would lean more towards punctuated equilibrium.

    Its perfectly fine if your expertise only addresses half the question in detail.

    Also, it is my understanding that all language is metaphor, even the one we are using now. So it is impossible to interpret something written 'literally'. But I believe the languages of science, especially math, are leaps and bounds more accurate metaphors than common tongue.

    The only thing is, that abstract metaphors touch our deeper human quality, such that we can feel its meaning, even if that meaning is different for everyone. It is a much more motivating force than more detailed experessions, such as numbers.
     
  8. Crunchy Cat F-in' *meow* baby!!! Valued Senior Member

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    Roy,

    Saquist has already answered the question... you just have to remove the extraneous words and understand what he is saying:

    "I believe ... a biblical perspective."

    Or specifically:

    "The bible validates what is true... not reality, observable phenomenoa, empirical data, or other myths."
     
  9. RoyLennigan Registered Senior Member

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    I would like him to explain, in this thread, what he means by that.
     
  10. iceaura Valued Senior Member

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    The two mechanisms you posit seem to me equally good candidates for the "macro" label, and equally dependent on small genetic changes - micro steps - followed by selection, being responsible for the large effects we observe.

    I don't think too many people who attempt to distinguish between "micro" and "macro" evolution would be willing to accept either of those mechanisms as the kind of distinction they sought.
     
  11. spuriousmonkey Banned Banned

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    Fixation on 'mutations' will blind you from the 'truth'. What is speciation really?

    Speciation occurs when a species can no longer be classified as the species it used to be. Because it has changed in form and/or behaviour.

    I'm not talking about how speciation might occur (for instance geographical isolation), but the result of speciation.

    Speciation produces something substantially new that distinguishes a population from the population it was derived from.

    Form and behaviour. Ultimately both are hardwired (to a certain degree) in the genetic material.

    Accumulation of mutations doesn't lead to speciation. Mutations that change form and behaviour leads to speciation. I think it is an important distinction to make.

    From a developmental perspective the genetic material is a tool. It's a black box to a certain extent, and it is extremely robust and at the same time malleable. The development leads to the same general type every single time. That is mighty robust. Signalling networks are so intertwined, backed up, 'redundant' that it is a miracle anything can actually change. It does. Small genetic changes can lead to big changes in form. Large genetic changes can fail to change the form.

    The entire fact that there is a system of complex developmental biology that leads to form and ultimately also a large set of behavioural patterns and/or restrictions is often overlooked. This system fucks up the entire notion of DNA being a blueprint. Mutation equals change. It is just not true. This entire concept of developmental biology also demolishes the concept of micro and macro evolution.

    An organism can accumulate a huge amount of genetic information that at first will not change form. The new neutral information can be used though to make major changes and do it quickly or slowly.

    Similarly small genetic changes can have major effects.

    How many generations does it take to turn one species into another?

    It is all entirely dependent on the developmental machinery, the genetic flexibility present that can support changes in this machinery and the environment (and a myriad of other things I do not mention). In the end it is all the same though. No difference between micro and macro.
     
  12. Ophiolite Valued Senior Member

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    I should rather say that behaviour that is facilitated by mutation leads to speciation.

    As a general remark, recall that I (and most biologists who use the term) would have macro evolution relate to higher taxonomic levels than species or genus.
     
  13. river-wind Valued Senior Member

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    in reply to both of Ophiolite's comments: why would the amount of change (speciation vs a new genus or a new family) or the speed of that change nessesitate a new mechanism?

    That accumulation of mutations that are not expressed versus a single mutation which triggers the expression of other features are still implimented one single mutation at a time. The results may be different, but aren't the mechanisms identical?
     
  14. Ophiolite Valued Senior Member

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    It may not necessitate a new mechanism, it may just be the way it is. It may be that without a further mechanism phylumisation (if I may coin a word) may not occur. I suggest we don't know. There is enough evidence out there to support either viewpoint.
    I know that on forums the defenders of evolution ignore many of the open questions about evolution in order to stave off the lunacy of the creationists. I suspect this might also influence many (most?) researchers, who will investigate the conventional line in more and more detail, rather than challenge what they understand to be the staus quo. It takes adventurers like Gould and Kaufmann to admit the difficulties and then to explore explanations for them.
    No. In the first case we have Darwin's slow gradual emergence of new species, and not a hope in hell by this means of evolving one of the higher taxa, certainly not a phylum. Look at the population from year to year and century to century you see no major differences.
    In the second case the new species, or higher taxa, emerges overnight - or at least in a single generation. That is a massive difference in my book.
     
  15. Saquist Banned Banned

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    Aside from the Biblical perspective there is the emperical perspective. That perspective is a different image from scientific theoretical perspective.

    The theoretical perspective is extrapolative, propposing a larger and larger picture over time. This perspective is also limmited by imagination and yet exagerates the emperical perspective. You refer to the exageration as "macro evolution" and the emperical perspective as "mirco evolution". The confluence of the two, what you dub "evolution."

    Revelations concerning the forward progression of DNA in cells has revealed with artifical alterations that mutation does not yield the necessary diversity to account for the complete restructuring of animal and plant kingdoms. While studies revealed plants were more suspectable to immediate change only 1% of those mutation induced in laboratories were benefical and animals produced results less than one percent favorable, outline by Wolf Lonnig.

    While that may have been the most latest revelation we've known about mutations harmful effects for sometime. There is consensus with Lonnig's findings.

    "Most of them are harmful or lethal" -Carl Sagan...

    "The greatest proportion of mutation are deleterious to the individual who carries the mutatated gene. It was found in experiments that, for every sucessful or useful mutation, there are many thousandss which are harmful."-Peo Koller

    "The fact that most mutations are damaging to the organism seems hard to reconcile with the view that mutation is the source of raw materials for evolution. Indeed, mutatants illustrated in biology textbooks are a collection of freaks and monstrosities and mutation seems to be a destructive rather than a constructive process"-Encycopedia Americana

    Placed in competition with normal insects purposefully mutated insects had a disadvantage.To that effect Stebbins says:

    "After a greater or lesser number of generations the mutants are eliminated."-G. Ledyard Stebbins

    Again in agreement with Lonnig's findings and mirroring observable realty.

    Isaac Asimov admitted: "Most mutations are for the worse." But then contradicted himself. "In the long run, to be sure, mutations make the course of evolution move onward and upward."

    Would any process that resulting in harm more than 999 times out of 1,000 be considered benefical? If a contractor had this sort or sucess ratio how long would he be employed. Would you feel safe with a driver that made this many bad decision vs good decisions.

    Essentialy this devision of marco and micro evolution is non-existent. Even if all mutations were benefical, they couldn't produce anything new.

    "A plant in a dry area might have a mutant gene that causes it to grow larger and stronger roots. The plant would have a better chance of survival than others of its species because its roots could absorb more water"-The World Book Encyclodpedia

    Nothing new. The may change color or textuture of hair and skin, or even add a sixth finger to hand of five but nothing new comes into existence.

    It does come down to odds and probabilty.

    "An accident, a random change, in any delicate mechanism can hardly be expected to improve it. Poking a stick into the machinery of one's watch or one's radio set will seldom make it work better." -Geneticist Dobzhansky

    It doesn't seem reasonable that the precision processes in a cell are built up by a procedure that tears down. The extrapolative perspective is directly contradicting the emperical perspective.

    The chances of even a simple protein molecule forming at random from the very begining 1 in 10 to the 113th power. Any event that has one chance in just 10 to the 50th power is regarded by mathematicians as never happening. That 10 to the 113th power is larger than the estimated total number of all the atoms in the universe.

    Hernandez Lemus of the Mexican International University in Mexico gives a 1 in 9 trillion odds of a chromosome evolving on it's own.

    No fewer than 2,000 proteins serving as enzymes are needed for the cells activity. The chances of obtaining all of these at random is 1 in 10 to the 40,000th power...."An outrageously small probability" -Fred Hoyle

    In his book with Chandra who I've quoted before Hoyle adds this: "that could not be faced even if the whole universe consisted of organic soup." then adds. "If one is not prejudiced either by social beliefs or by a scientific training into the conviction that life originated [spontaneously] on Earth, this simple calculation wipes the idea entirely out of court."

    The chance of forming histones, thought to govern gene activity, at the simplest to be one in 20 to the 100th power, another huge number. That is "larger than the total of all the atoms in all the stars and galaxies visible in the largest astronomical telescopes."

    "Preoteins depend on DNA for their formation. But DNA cannot form without pre-existing protein." Hitiching

    - "Which came first,"- [/B]"The answer must be they developed in parallel."
    -Richard E Dickerson

    Evolutionary theory attempts to eliminate the need for the impossible to be accomplished in one blow by espousing a step by step process by which natural selection could do it's work gradually. However, without the genetic code to begin reproduction, there can be no material for natural selection to select. This is our emperical perspective. The theoretical perspective is massively misproportioned and contradictory to reality and it's emperical foundation.
     
    Last edited: Apr 13, 2007
  16. Ophiolite Valued Senior Member

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  17. Saquist Banned Banned

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    Very good Ophiolite...that's exactly what I would do in such an impotent position....crap.
     
  18. Saquist Banned Banned

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    How far did you get before you had that emotional reaction, Ophiolite.?(purely in the intrest of behavorial observation)
     
  19. Ophiolite Valued Senior Member

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    I saw your name and didn't need to read any further.

    By the way, it wasn't an emotional reaction, it was a carefully judged, objective, scientific assessment.
     
  20. Saquist Banned Banned

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    I implore you to continue to do so. Listening is not one of your cardinal attributes.
     
  21. river-wind Valued Senior Member

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    Saquist: http://www.sciforums.com/showthread.php?p=1354522#post1354522
    You present a better case here than you have previously. However, you are off-topic. Please discuss the division between micro and macro evolution in this thread, not the validity of abiogenesis.

    But why? I don't see a difference, other than the time in which it occurs. Why is it that 'slow' acts as a prophylactic to divergence?
     
  22. spuriousmonkey Banned Banned

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    god dam it you fuckers. The first decent thread in years and now it is fucked up.
     
  23. Saquist Banned Banned

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    True but no matter where along the progress of what is called evolution we must face facts and we must face the odds. Micro evolution is adaptation, observed and completely emperical. Marco evolution is imaginary, theoretical, improbable, and mathematically impossible. These individuals had already come to this conclusion and no significant research to explore the limmits of evolution or micro evolution existed untill Lonnig established the Law of recurrent variation. A dilberate attempt to isolate adaptive features in living organism...moving biology out of the realm of theory. Michael Behe also sough to define a limmit, Proposing that cells could not maintain function or develop in reduced states.

    This is not the first time voices have been heard on this subject. People like Ophiolite use deaf ears as measure of credibility but a deaf man never heard anything worthwhile.
     

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