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Evolutionary feedback

  1. Jun 16, 2003 #1

    drag

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    Greetings !

    I realize that evolution goes on due to random mutations
    of individuals in the spicies and then survival of
    the fittest along a sufficiently long period of time.
    My question is, and please go easy on me 'cause
    I know very little about this stuff, is it all random like
    I discribed or is there a certain feedback also involved
    in terms of a single individual from the environment.
    I mean if one organ is used more than it's supposed to
    and another one is used less by a single creature would
    it somehow provide a feedback to the genes or is it all
    just random and separated by generations of creatures ?
    (I guess not since each gene is supposedly responsible of
    a whole organ or whole parts of an organ and there's
    supposedly nothing internal to change in it plus you'll
    have to change other genes - organs for the relevant one
    to evolve accordingly in the next creature, but I was just
    wondering whether something like that is known and/or possible.)

    Thanks ! :smile:

    Live long and prosper.
     
  2. jcsd
  3. Jun 17, 2003 #2
    That's commonly referred to a Lamarkian Evolution and it's false. There is no feedback from the environment that alters an organisms germline (cosmic and nuclear radiation can do but that's not feedback)

    The only feedback that effect a genes proliferation is differential survival and reproduction.
     
  4. Jun 17, 2003 #3
    this is wrong. these do not actually give feedback. this is the process by which a gene that has undergone a mutation (the only feedback) is selected as beneficial to the organism. the only change for a gene line is random mutation and sexual mitosis.
     
  5. Jun 17, 2003 #4
    No that is not wrong. I said "The only feedback that effects a genes proliferation is differential survival and reproduction."

    Please tell me how that is wrong.
     
  6. Jun 17, 2003 #5
    This however is wrong.
     
  7. Jun 17, 2003 #6
    I would ordinarily agree with you. But lets not be to hasty. I saw a documentary the other day about an Aussie scientist, Ted Steele, looking at a possible lamarckian mechanism in immunology I think it was. His work sounds interesting, but I don't know enough to comment further.
     
  8. Jun 17, 2003 #7
    I'd be interested in hearing about it if you can dig something up. Given the germline is sectioned off after 52 days of embryo development I'd find that sort of discovery very interesting.
     
  9. Jun 17, 2003 #8

    iansmith

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    Evolution of one species is not entierely due to random mutation some selfish DNA/gene (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6245369&dopt=Abstract) such as plasmid, transposon and virus, and gene transfert can contribute to evolution. In bacteria, genome of some pathogen exhibited difference in G-C concentration in their virulence gene. It is theorized that these genes were acquire from a different organism.

    PaulyMan, I also saw an article on the scientist you are talking about. In think the article waas in scientific american.
     
  10. Jun 17, 2003 #9

    Phobos

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    I'll just note that it seems* that 1 gene doesn't do just 1 thing...there seems to be interactions between genes (holistic results). So maybe there's some kind of feedback potential there. Is there a geneticist in the house?

    * - e.g., from the recent finding that humans have fewer genes than initially suspected
     
  11. Jun 17, 2003 #10

    iansmith

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    Phobos the 1 genes 1 function is an old idea. We have known for a while that 1 genes can do more than one function. The multiple gene function is due to post -transcription, translation and post-translation editing, and regulation (protein-DNA and DNA-DNA interaction). So one gene can give many different gene product. Regulation and editing of gene will enhance feedback because it could increase the survival rate of the indiduals carrying this mechanism.

    There also gene duplication where 2 genes codes for the same of kind protein and both gene have the same function (no significant difference). This can be common in bacteria.

    The number gene in the human has been going down since they started to sequence it. I think the older numbers were overestimate due to our ego. Nature has good ways to shows us how to be humble.
     
  12. Jun 17, 2003 #11

    drag

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    Greetings !

    Thank you all for your input ! :smile:

    A more particular thing that occured to me that is directly
    related to my question: If a certain organ is used less
    than a certain other organ, for example, then is it not the
    case that the related genes affecting the cell reproduction
    (I think that's how it goes, again I practicly know nothing
    on the subject) will be somehow less active in this whole
    proccess ? I mean, after all, there is some sort of primary gene
    or something in a cell that takes "control" and decides what
    type of cell that cell will form into, is that correct ?

    Anyway, if that is the case then would it be possible that
    this will also effect the activity and hence mutation rates
    of the relevant genes in the sperm or whatever other means
    of genetic info transfer that takes place when a new generation
    of creatures is concieved ?

    Thanks ! :smile:

    Live long and prosper.
     
    Last edited: Jun 17, 2003
  13. Jun 19, 2003 #12

    Another God

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    That is an interesting thought Drag, but in terms of population dynamics and evolution, all of the cells in our body, and all of the DNA within them , are all dead ends. They are cell lines doomed to extinction all for the chance of perpetuating one small cell line which exists down in the gonads....

    Oh the dedication to their nation....

    Anyway, yeah, so your idea is neat. It is a fact that our bodies have evolved to this point where our bodies physically adapt due to use and disuse (build up your muscles, grow calluses etc). So, if a body doesn't use something at all, then it makes sense that the body would grow that organ/whatever less, and it is also possible that the body would pay less attention to monitoring the mutation rate within the cellular DNA. Having said that though, because the organ is growing less, the DNA is dividing much less, so there is less chance for mutation. There are also less cells present, so a naturally lower probability that a random mutation will occur.


    So yeah, thats my take on this idea of yours. The most important thing for you to note though, is the fact that the DNA within these cells is not passed on to offspring, so they cannot affect the evolution of this species. The only mutations which affect the generations to come, are mutations which occur from the recombination between mother/father DNA, mutations which occur in the sperm/egg or in the zygote/embryo itself.
     
  14. Jun 20, 2003 #13

    drag

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    Greetings !
    So, you're saying there is no effect of these possible
    effects in the body on the sperm/eggs ?

    Live long and prosper.
     
  15. Jun 20, 2003 #14

    Another God

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    There is negligable chance. Close enough to zero for me to be able to have just replied zero, but i like to be accurate in these things. There is completely negligable chance that the DNA, within the cell of an organ not related to the teste's, will in some way increase the number of mutations present, and then transfer these mutations into the DNA of a cell within the testes, and then have these mutations copied into every sperm cell from then on...

    Not gunna happen.
     
  16. Jun 21, 2003 #15
    Perhaps the "feedback" comes from "within" an organism...in the "form" of INTENTION. Perhaps -- somehow, some way -- the proto-humming bird once "said" to itself: "Gee, if only my beak were a little longer..."

    There are schools of thought -- ABOUT "thought" -- that suggest that there's a "kernal of consciousness" if every cell and elementary particle (not to mention complex systems, biological and not) that might serve to direct information to, well, Everything Else.

    And what is thought of as "random processes" might "simply" (I always have to put THIS word in quotes...'cause nothin's "simple"!) be a "gateway" between that which is "potential" and that which has (or will) become "real".

    And, it might be that INTENTION is a natural ingredient of the Universe -- macro and micro -- that impinges upon the "lynchpin" of "randomness" CAUSING certain potentialities to manifest while others do not.

    Thus, evolution might be driven by a simple (I gotta stop with the quotes) fundamental question, which if articulated, might sound something like this: "What do I need next?"

    Now, what I -- M. Gaspar -- personally need next are replies that tell me why INTENTION can or cannot be a "force" in the Universe...or, why CONSCIOUSNESS can or cannot be "imbedded" in every spec and complex system of baryonic matter.

    What I do NOT need is a KICK in my intellectual teeth.

    I W : be kind.
     
    Last edited: Jun 21, 2003
  17. Jun 21, 2003 #16

    drag

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    Greetings !

    AG, I'm not certain we understood each other. I was
    not talking about some type of mutation taking place
    and reproducing sufficiently or something.

    I was inquiring about the relative amount of cells in each
    organ (more/less developed organs) somehow affecting the
    sperm/eggs cells. Guess abviously not. Anyway, Thanks ! :smile:

    M. Gaspar, this is or at least was a discussion about
    evolution specificly, not its credibility as a scientific
    theory or unscientific assumptions.

    Peace and long life.
     
  18. Jun 21, 2003 #17

    Another God

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    And besides, when u understand that a mutations is just the change, removal, or addition of a segment of DNA (ie: Adenine, Guanine, Cytosine and Thymine combinations), you quickly see how simple a mutation is, and how 'thoughts', 'wishes', 'desires' etc have ABSOLUTELY no say about what happens. The only thing which has any say, are things like Radiation and mutagen chemicals, and the say they have is hardly directed. Its "random".

    Oh, and the consequences are a long way down the track once that simple DNA mutation has occured. You still have to transcribe the DNA into RNA (If that even happens to it), you still have to translate that RNA into DNA (If that even happens to it), and then the protein that results must be structurally altered into a primary, secondary, tertiary and quaternary structure...after which it can then start serving its role, which is usually a much simpler part of a larger system of reactions that catalyse the production of 'Something'

    LOL...Creationists... "A mutation is a bad thing that happens to creatures, which results in deformities!!!"

    HAHAHAHA. If only they had a clue.
     
  19. Jun 21, 2003 #18

    Didn't I ask you to be kind?

    Do you think I'm a "creationist" because I'm wondering about INTENTION? Do you think that I think that "God" -- the Great Outsider -- created Everything through some "Divine Will"?

    That's not what I'm saying at all.

    And if YOU, Drag, are saying that your discussion is being rudely interrupted by the insertion of a POSSIBILITY to which you do not subscribe, then I say.... .

    Further, my post offers a "proposition"...not an "assumption".
     
    Last edited: Jun 21, 2003
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