Have we stopped evolving.

Discussion in 'Biology & Genetics' started by Halo, Oct 15, 2002.

  1. A Canadian Why talk? When you can listen? Registered Senior Member

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    yes mankind is always evolving....
    but we have interfeared with natural selection.
    only the strong survive....

    with hospitals curing thousands of desises every day, how can we let mankind evolve naturaly?

    we are screwing up the system!
     
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  3. paulsamuel Registered Senior Member

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    reply to spuriousmonkey

    This is probably the source of a fruitful discussion, i.e. your response to my statement that "Evolution is quite simply the change in gene frequencies over time." I emphatically support this definition as do most of us (evolutionary biologists), and texts that I've seen use this definition (e.g. Evolutionary Biology, Futuyma).

    You are correct in your views on natural selection. It cannot be understated how important natural selection is in evolution.

    But ("everyone has a big but," PeeWee Herman), you are wrong when you imply that there is no evolution without natural selection.

    There is evolution without selection. In the neutral theory of evolution (or the nearly-neutral theory of evolution), there are characters, both molecular and morphological, that are neutral (not subject to selection) and these characters change over time (evolve) precisely because they are neutral. i.e. characters under selection tend to be very stable and change little over time. The stronger the selection, the more stable (unchanging) the character. For example, actin genes in insects and mammals are virtually identical because selection maintains stability in the actin genes. The neutral theory came about (I think in the 1970's or 80's) when pop. geneticists and molecular taxonomists discovered that many enzymes had 2 or more forms (morphs called allozymes) that appeared to perform equally well functionally. Since, many morphological and molecular characters have been found that are neutral and it turns out that these are the best characters to use in systematic studies (i.e. taxonomy). So, when neutral characters change in populations this is still evolution, although no natural selection has taken place.

    Strict adaptationists are rare now in evolutionary biology. Most of us agree now that evolution can and does occur by chance and random events alone, e.g. genetic drift.

    I am quite familiar with evo-devo, thank you, but had not heard of eco-devo ("eco-devo,.... the ecological, adaptive, and microevolutionary parts of evo-devo... include ..... phenotypic plasticity, environmental sex determination, endocrine disruption, life history strategies, and adaptations of developmental stages to environmental conditions"). I have not read any papers on this yet (would appreciate journal refs if you have them, but it doesn't sound too different from evo-devo and is apparently a subset of evo-devo studies).
     
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  5. paulsamuel Registered Senior Member

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    reply to inspector

    as I thought, you ARE a religious fanatic trying to pass off religious beliefs as science! however most readers of these forums are too intelligent to be taken in by your misleading statements, pseudoscience and outright lies.

    evolution occurs, and is the means of speciation. taxa diverge when genetically isolated, time increases this divergence, hence macro-evolution. there are many scientific comparitive studies supporting macro-evolution, there are NONE that do not support it. this is not circular at all, it is quite direct.

    I find your attempts to obfuscate real scientific research and confuse those attempting to learn and understand, dispicable.

    BACK!! BACK I SAY!! BACK TO THE RELIGION FORUM WHERE YOU BELONG!!
     
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  7. paulsamuel Registered Senior Member

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    reply to spuriousmonkey

    you said,

    " If you follow this statement true, we would then have to say that any mutations that are harmful will not persist in a population. They will therefore not increase in your precious gene frequency."

    We know this is not true. It depends on strength of selection, epistatic effects and pleiotropic effects.

    you said, " i can't actually think of that many other important mechanisms that provide for genetic variation other than mutations, be it point mutations, deletions, duplications etc. so i was wondering what you were talking about."

    actually, we generally mean point mutations and insertion/deletions when we say mutation, but if you want to include duplications, unequal crossing over, polyploidy, etc. as mutations, then that's fine with me. I generally won't get into discussions about semantics.
     
  8. Adam §Þ@ç€ MØnk€¥ Registered Senior Member

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    Paulsamuel

    Rest assured, most of us have read at least something, and are aware of the supporting evidence for evolution. Inspector has come across a few terms from the field and throws them in among his fanatical ramblings in the hope of seeming somewhat informed, but he's pretty transparent.
     
  9. spuriousmonkey Banned Banned

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    24,066
    eco-devo

    a news feature in 'nature'

    Nature 418, 578 - 579 (2002); doi:10.1038/418578a

    and a review in 'developmental Biology'
    REVIEW
    Ecological Developmental Biology: Developmental
    Biology Meets the Real World
    Scott F. Gilbert
    Developmental Biology 233, 1–12 (2001)
    doi:10.1006/dbio.2001.0210, available online at http://www.idealibrary.com

    i actually don't know if you have seen Scott Gilberts latest talk, but he is pressing that we should use developmental biology instead of population biology to teach evolution. It was quite interesting although I might not agree with it in every detail.

    +++So, when neutral characters change in populations this is still evolution, although no natural selection has taken place.+++

    although it might be part of the evolutionary process but I wouldn't classify it as evolution since basically we just talking about change and not functional change. Although it is interesting aspect of evolution it doesn't quite shape the living world we see, accept possibly by providing an extra means of accumulatiing variation.


    +++actually, we generally mean point mutations and insertion/deletions when we say mutation, but if you want to include duplications, unequal crossing over, polyploidy, etc. as mutations, then that's fine with me. I generally won't get into discussions about semantics.+++
    i see your point now, and i guess for most people mutation is merely a point mutation, but i'm looking at it as a biologist and when i think of mutation i automatically think of all aspects of mutation. At least thats how they teach it to us. But i can see that you want to stress that mutations are not just a point mutations since most people are not that well informed (probably especially on an open forum.)


    and for macrovolution: it is quite clear that there is macroevolution (otherwise there wouldn't be species), but the exact mechanisms might not be totally clear yet. But that's with most things in science. Don't worry about it. science would be quite boring if we had all the answers with every detail sorted out. In fact, we could stop doiing science.

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    Last edited: Dec 5, 2002
  10. paulsamuel Registered Senior Member

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    reply to spuriousmonkey

    thanks for the refs.
     
  11. inspector Registered Senior Member

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    "I find your attempts to obfuscate real scientific research and confuse those attempting to learn and understand, dispicable."
    ----------------------------------

    Put your personal opinions and character attacks aside. I am not here to confuse anyone, but rather, to demonstrate to those who believe in the fallacy of evolution how their logic is flawed. Unfortunately, those who oppose evolution, including many scientists, are immediately labled Creationists simply because they expose the innumerable errors of evolutionary theory and offer alternative explanations. I am merely stating that macro-evolution is a lie and whoever believes in this fallacy is being misled. Do not be afraid of healthy debate and do not run away. I every right to expose the errors of evolutionary theory here as you have the right to support it. We are discussing evolutionary theory here, not religion. Stick to the topic.

    Now, give me a specific, scientifically-proven, valid example that macro-evolution has occured in the past.
     
  12. spuriousmonkey Banned Banned

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    could you give a definition of macroevolution first...there have been so many definitions that it is difficult to guess what you might think macroevolution is

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  13. inspector Registered Senior Member

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    "could you give a definition of macroevolution first...there have been so many definitions that it is difficult to guess what you might think macroevolution is"
    -----------------------------


    Macro-evolution is defined as an organism acquiring, through mutation, a completely new gene which was not present in any of that organism's ancestors. Do you accept this definition, or would you like to submit an alternative definition?
     
  14. paulsamuel Registered Senior Member

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    882
    inspector is ignored

    just ignore inspector. beliefs are unassailable because they can't be disproven. also, who cares? finally, scientific discussions will not be aided by including religious beliefs.
     
  15. inspector Registered Senior Member

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    Sam,

    This is a discussion about evolution. Do you always run when someone challenges your presuppositions? Or, are you simply afraid that someone may actually expose the error in those presuppositions that you hold? Stick around, you might learn something.
     
  16. (Q) Encephaloid Martini Valued Senior Member

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    Inspector

    Macro-evolution is defined as an organism acquiring, through mutation, a completely new gene which was not present in any of that organism's ancestors. Do you accept this definition, or would you like to submit an alternative definition?

    I would define macro-evolution as the splitting of a species into two or the change of a species over time into another. Perhaps your definition is closer to the definition of micro-evolution.


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  17. inspector Registered Senior Member

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    Q, since I respect your ever-intelligent input, how can macro-evolution (being non-testable) be proven, given that macro-evolution contradicts the second law of thermodynamics, and, is based on the foundation of a flawed geologic column?
     
  18. (Q) Encephaloid Martini Valued Senior Member

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    Inspector

    how can macro-evolution (being non-testable) be proven, given that macro-evolution contradicts the second law of thermodynamics

    That is a question of immense magnitude which needs to be broken down and examined carefully. Can I presume your overall argument is the common misconception that macro-evolution of complex life-forms from single-celled life-forms could not have occurred due to order arising from disorder ?

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  19. inspector Registered Senior Member

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    "Can I presume your overall argument is the common misconception that macro-evolution of complex life-forms from single-celled life-forms could not have occurred due to order arising from disorder ?"
    ---------------------------------

    Q, you might want to lose the fish thing, or you may be accused by some of spreading subliminal religous messages. ;-) I think your idea of breaking down and examining the equation is a wonderful idea. At this point, I am simply addressing the improbabilities of random ordering from a non-ordered state. An example is a snowflake -- or any crystallization. Crystallization, however, happens to specific elements at specific times under specific conditions. It is a phenomena that is intrinsic to the atomic structure of the element or compound being considered. It is not a random ordering of a material from a non-ordered state, but rather the result of a specific design involved in the material and can be counted on to happen every time under the prescribed conditions. What is interesting, however, about this particular thing, is that there is a heat transfer involved in crystallization and the second law of thermodynamics is not violated therein. Heat is diffused.

    Biological increase in complexity is exemplified by a seed becoming a bush or flower or tree, or a fertilized egg becoming a person. However, the design is already present in these beginnings of life. The DNA is there from the beginning, along with whatever might be "sparking" it, and the rest is simply a matter of following instructions. It is, again, not a random ordering from a non-ordered condition. It is a design being executed. As in the case of crystallization, the execution of the biological design requires specific environmental requirements or it cannot proceed. Perhaps it should also be mentioned that evolution, as inferred from the fossil record, is not even a theory. Theories are testable and, ideally, falsifiable. Evolution is neither. It is, therefore, simply an idea. For some a belief, perhaps, but it cannot be rightly called either fact or theory when it refers to the "bacteria to bears" progression. Are you with me so far?
     
  20. (Q) Encephaloid Martini Valued Senior Member

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    Inspector

    Q, you might want to lose the fish thing, or you may be accused by some of spreading subliminal religous messages.

    Did you think I was going to let you get away with posting your Jesus fish ?

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    Crystallization, however, happens to specific elements at specific times under specific conditions.

    Crystallization requires that a solution become "super-saturated," or quite simply, the state in which the solution contains more dissolved solids than can be accommodated at a given temperature. There are four common methods of attaining super-saturation of which cooling is the primary and most common method. And although this is nearly always the case, there are exceptions.

    It is a phenomena that is intrinsic to the atomic structure of the element or compound being considered.

    Actually, crystallization occurs at the molecular level - and those molecules in the crystal are clearly more ordered than the molecules randomly moving in a solution.

    What is interesting, however, about this particular thing, is that there is a heat transfer involved in crystallization and the second law of thermodynamics is not violated therein. Heat is diffused.

    The increase in entropy is defined as heat assimilated by a system divided by the absolute temperature at the time the heat was absorbed. In a salt-water solution for example, the entropy of the crystal decreases upon formation, and the entropy of the water increases as it evaporates. Therefore, the increase in entropy of the water is greater than the decrease in entropy of the crystal - the overall net entropy increases.

    This clearly invalidates the argument regarding the improbabilities of random ordering from a non-ordered state.

    Moving on...

    However, the design is already present in these beginnings of life. The DNA is there from the beginning, along with whatever might be "sparking" it, and the rest is simply a matter of following instructions. It is, again, not a random ordering from a non-ordered condition. It is a design being executed.

    Intelligent design ?

    Hardly. It can be shown that DNA did not collect purely by chance, but instead, a combination of chance and the laws of physics. For example, the nuclear force is required to bind neutrons and protons in atoms, electromagnetism is required to keep atoms and molecules together and gravity was needed to keep everything fixed to the surface of the Earth.

    If any of these fundamental forces by nature had appeared with slight variations in their strengths, the universe might never have formed the heavy elements, such as carbon, necessary for life.

    Theories are testable and, ideally, falsifiable. Evolution is neither. It is, therefore, simply an idea.

    Evolution is both a theory and a fact. Evolution is a fact because the existence of biological evidence is overwhelming, and continues to grow. Evolution is a theory because the mechanism which drives evolution is not completely understood, and while several theories are being examined, biologists are still uncertain as to the exact mechanism.

    Are you with me so far?

    Right on top of things, as usual.

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    Do you now see the course tendencies of the fish ?

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  21. inspector Registered Senior Member

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    "Evolution is a fact because the existence of biological evidence is overwhelming, and continues to grow."
    ------------------

    What biological evidence? Q, you are certainly sharp enough to understand that if there are equally valid alternative explanations, those things cannot be claimed as evidence. However, I am willing to examine what you are labeling as biological evidence of macro-evolution. Proceed.




    "If any of these fundamental forces by nature had appeared with slight variations in their strengths, the universe might never have formed the heavy elements, such as carbon, necessary for life."
    --------------------

    I noticed you used the word "might never have...". Obviously, this is a subjective statement and I, likewise, could offer my alternative theory that would be subjective, also.




    "Did you think I was going to let you get away with posting your Jesus fish ?"
    --------------------

    I do not understand what you are referring to when you say MY fish. This is a scientific discussion about evolution and it's flaws, remember? ;-)
     
  22. (Q) Encephaloid Martini Valued Senior Member

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    Inspector

    What biological evidence?

    Come now, are you trying to tell me no one here has presented this evidence for you to examine ? I myself have posted such evidence in other threads. Very well, then:

    The Fossil Record - identifies the sequence of biological life-forms which changed systematically over long periods of time.

    Common Structures - identifies and infers a common structure in anatomy between animals which, although may vary in detail, are similar in general structure and relation to one another.

    Species Distribution - identifies the diversity of life throughout the world.

    Development Similarities - identifies the similarity of genes across a wide range of organisms during the development from the time of conception.

    Molecular Biology - This area represents massive amounts of evidence and information, far too much to post here. However, I can provide an example - the code used to translate nucleotide sequences into amino acid sequences is essentially the same in all organisms.

    I noticed you used the word "might never have...". Obviously, this is a subjective statement and I, likewise, could offer my alternative theory that would be subjective, also.

    Sorry, I will then substitute "might never have" with "most certainly would not have." The universe would be pure hydrogen at one extreme, or pure helium at the other.

    This is a scientific discussion about evolution and it's flaws, remember?

    No, the title of the thread is, "Have we stopped evolving," which imo, is a very good question. But of course, the only answer to that question is, "No, we have not stopped nor will we ever stop evolving."

    Be the fish! Oops! We already were.

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  23. Adam §Þ@ç€ MØnk€¥ Registered Senior Member

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