Saturday, March 27, 2010

Histone Inspectors: Codes and More Codes

By now most people know about the DNA code. A DNA strand consists of a sequence of molecules, or letters, that encodes for proteins. Many people do not realize, however, that there are additional, more nuanced, codes associated with the DNA. For instance, minor chemical modifications (such as the addition of a methyl group) to the DNA provide bar-code like signals to the protein machinery that operate on the DNA. This DNA methylation influences which genes, along the DNA strand, are read off. And this DNA methylation itself may be modified to provide additional information.

Or again, the DNA is wrapped around histone proteins, and these histones are also bar-coded. The histones have a hub, around which the DNA wraps, and a tail that sticks out on which chemical tags are attached. Again these tags are signals for the protein machinery. Furthermore, these tags are removed as well. Such modifications and removal of these chemical tags means that these codes are dynamic, and there are protein inspectors that double-check these complex encodings.

These subtle codes are also context dependent. In one type of cell a histone modification may turn off a gene whereas in another type of cell the same histone modification may turn on the gene.

New research has elucidated some of the structural details of the histone inspectors. This is important research because these subtle codes, and associated machinery and mechanisms, are not yet fully understood. They have profound biological impact, but we still have much to learn about how it all works.

Needless to say the idea that all of this arose on its own, as a consequence mutations and the like, luckily putting together such intricacies, is beyond silly. Religion drives science, and it matters.

18 comments:

  1. Like macros.

    #ifdef _CANE_TOADS_PRESENT_
    #compilewith _VENOM_IMMUNITY_
    #elifdef _WARM_WEATHER_
    #compilewith _MINIMIZE_BODY_VOLUME_

    ReplyDelete
  2. So what hypotheses do you...

    Ken Miller suggests God could work through Quantum Mechanics but Common Descent is well supported by the evidence.

    Michael Behe suggests Random Mutation does not explain it but Common Descent is well supported by the evidence.

    Francis Collins suggests life and nature are too complex for there not to be a God but Common Descent is well supported by the evidence.

    What was your position on the Common Descent again?

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  3. Thought:

    "What was your position on the Common Descent again?"

    It is helpful to understand the basis for claims that this or that theory is a fact, or compelling, etc. For instance, claims that evolution or common descent are a fact or compelling are metaphysical--they rely on non scientific premises.

    From a scientific perspective, OTH, the empirical evidence does not bode well for these theories. See the first half of this post, for instance:

    http://darwins-god.blogspot.com/2010/03/evolution-one-in-billion-shot.html

    So there you have it. These theories can be compelling, or weak, depending on one's perspective.

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  4. Dr. Hunter,

    I take it a summary of your position is that... "From a scientific perspective, OTH, the empirical evidence does not bode well for these theories."

    Here is Behe's take.
    "...in judging the likelihood of common descent, I discount problems that could be classified as "how did that get here?" Instead, I give much more weight to the "mistakes" or "useless features" arguments. If some peculiar feature is shared between two species which, as far as we can tell, has no particular function, and which in other contexts we would likely call a genetic accident, then I count that as rather strong evidence for common descent. So, if one looks at the data in the way that I do, then one can say simultaneously that: 1) CD is very well supported; 2) grand Darwinian claims are falsified; 3) ID is confirmed; 4) design extends very deeply into biology."
    http://www.discovery.org/a/4097

    And again...
    "I take pseudogenes as good evidence of common descent, both in Darwin’s Black Box and The Edge."
    http://www.amazon.com/gp/blog/post/PLNK1ACOEMDSY2DKV


    Why should a layperson take your interpretation as "fact" instead of listening to theistic biologists like Behe and Miller or geneticists like Collins?

    To me, the idea that humans and chimpanzees share a common ancestor appears to be well supported by the evidence because of evidence like the shared "genetic accident" of an inability to biosynthesize vitamin C.

    In contrast, the Theory of Gravity looks very shaky. Physicists know it is due for a paradigm shift once they come up with a workable hypothesis.

    Throwing stones at existing theories, be it for gravity or evolution, is easy. The hard part is suggesting and defending an alternative.

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  5. Thought:

    "Why should a layperson take your interpretation as "fact" instead of listening to theistic biologists like Behe and Miller or geneticists like Collins?"

    Instead of? I don't see why it is an either or.

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  6. Dr. Hunter,

    "Instead of? I don't see why it is an either or."

    This is why I asked you to restate your position on Common Descent.

    The only thing easier than throwing stones at an opposing idea, is to throw stones at a vague idea supported by nameless, faceless "evolutionists".

    I have identified three prominent evolutionists who all believe Common Descent is well supported by the evidence.

    They also provide an explaination for the existance of "Codes and More Codes". In short, they attribute it to God's will.

    I, and many other observers interested in science, leave the metaphysical questions to the philosophers. Whether the ultimate source of life is randomness, quantum effects or God isn't a question science can answer at this time. It is likely science will never be able to fully answer it.

    Yes, everyone has a philosophical outlook that colors their perceptions (including myself).

    It is my perception Common Descent is well supported by the evidence whereas the Theory of Gravity is not.

    The effects of what we call "gravity" are a fact (observation).

    The effects of what we call "evolution" are a fact (observation). Living things change over time.

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  7. Thought:

    "I have identified three prominent evolutionists who all believe Common Descent is well supported by the evidence."

    But those are metaphysical arguments. I fully agree there are strong metaphysical arguments.

    "Why should a layperson take your interpretation as "fact" instead of listening to theistic biologists like Behe and Miller or geneticists like Collins?"

    You're finding a contradiction where there is none.

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  8. Dr. Hunter,

    I honestly don't know which would be worse. You actually believing your twisted reasoning and inferences or intentionally providing misinformation for propaganda purposes. I suspect it is a little of both.

    Gravity warping space is much more metaphysical than commonality in DNA sequences and vitamin C processing functions. However, you appear to hold physicists to a different standard than evolutionists.

    I think the grownups in the room understand why that is so.

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  9. Thought P.

    Get real for petes sake.

    "twisted reasoning and inferences"
    Good Lord man, wake up and smell your own feces!

    All of the most twisted reasoning is to be found in Darwinian "logic" if I may abuse the word here.

    "grown ups in the room"?
    You ought to become one sooner or later I suppose if you keep trying.

    What a pompous jackass you are, TP! Just like all the other brain dead Darwinian fundamentalist preachers.

    You jerks think you are so smart with your ubiquitous lines of perpetual double talk, hand waving, fallacious ideas & condescension, but you are just "mentally ill" as F. Hoyle stated so succinctly.

    Go ahead now, accuse me of something you yourself are deeply guilty of in this very thread; I won't be reading any more of your laughable trash anyway.

    CD?
    I have many CD's
    I believe, with "mountains of overwhelming evidence", that they all descended from a first CD - possibly by Jubal.

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  10. me: "I think the grownups in the room understand why that is so."

    Hitch: "What a pompous jackass you are, TP! Just like all the other brain dead Darwinian fundamentalist preachers.

    You jerks think you are so smart...

    Go ahead now, accuse me of something you yourself are deeply guilty of in this very thread; I won't be reading any more of your laughable trash anyway."


    If hitch wanted to be counted as one of the grownups in the room, he probably shouldn't have engaged in the equivalent of putting his fingers in his ears and calling me names.

    However, let's examine this name-calling starting with "pompous jackass". This isn't totally inaccurate but in most polite conversation just the adjective "pompous" would be used leaving the commonly modified noun implied. It is by this token I have often been called "arrogant" with its noun most often implied but occasionally stated. I would agree that I am arrogant.

    Hitch’s use of the term “jerks” was mostly gratuitous as a preamble to channeling the man who coined the term “Big Bang” as a joke because he thought it was ridiculous until he suddenly decided to become evangelical and promote creationism with his Hoyle’s Fallacy which biologists universally dismiss. Naturally, Hoyle chose to believe all biologists are crazy instead of conceding they have a point.

    Accusing me of being a Darwinian Preacher doesn’t fit the facts unless, of course, a “Darwinist” is defined as anyone who doesn’t support the religious movement promoted by the Discovery Institute. Behe believes Common Descent is well supported by the evidence, is he a “Darwinist”? Or is he exempt because he is a fellow at the Discovery Institute?

    If one takes the time to look at my past posts, they should realize I am taking Behe’s idea to the next step. Behe focuses on the molecular level to suggest limits to what randomness can do. I focus on the quantum level to suggest randomness is completely powerless because it doesn’t exist. And since consciousness is very probably the direct result of Quantum Biophysics, this is a hypothesis as to how life on Earth is the result of consciousness. Why would anyone interested in exploring the SCIENCE of Intelligent Design have a problem with this?

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  11. There is any place where you explain what consciusness means for you and how it replace ramdomness?

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  12. Hi Blas,

    Here is a reasonable source for finding out about quantum consciousness.
    www.quantumconsciousness.org

    In short, if you presume consciousness is more than just an emergent property of the brain processing logical algorithms then it needs to come from a non-deterministic source.

    The only non-deterministic source we know possibly exists is from Quantum Mechanics (and for those who believe, God).

    Penrose/Hameroff hypothesized the microtubules in the brain act like quantum computers. Many scientific papers have been published arguing for or against this hypothesis. Recent discoveries of life directly using Quantum Mechanics are lending support for this hypothesis.

    Consciousness is one of those properties which are hard to define. If consciousness truly comes from quantum effects and these quantum effects are truly non-deterministic then a complete understanding will forever be beyond the reach of science.

    It could be possible God and our individual souls are behind the quantum effects undetected.

    It also could be possible quantum effects are random and everything is the result of shear dumb luck.

    It also could be possible all quantum effects are interconnected and "orchestrated" which means our consciousness is linked to the universe.

    I hope I have answered your question.

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  13. "It also could be possible quantum effects are random and everything is the result of shear dumb luck."

    So you are proposing that instead darwinist ramdomnes evolutin is guided by something that could be ramdom?

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  14. Hi Blas,

    If Dr. Hunter would limit his complaints to Quantum Mechanics, I would readily agree with him because it is just as much a metaphysical assumption to say quantum uncertainty is random as it is to say God controls it.


    Are you familiar with "Laplace's demon"?

    Laplace wrote...
    "We may regard the present state of the universe as the effect of its past and the cause of its future. An intellect which at a certain moment would know all forces that set nature in motion, and all positions of all items of which nature is composed, if this intellect were also vast enough to submit these data to analysis, it would embrace in a single formula the movements of the greatest bodies of the universe and those of the tiniest atom; for such an intellect nothing would be uncertain and the future just like the past would be present before its eyes."

    Before Quantum Mechanics was discovered it was generally accepted the entire universe was deterministic. "For every action there is an equal but opposite reaction" and so forth. Nothing was left to chance. Any appearance of randomness was due to complexity and insufficient information. Nothing is truly random in pure Newtonian physics.

    Quantum Mechanics changed all that.

    It is the only possible source of true randomness but we don't know and probably will never know. Therefore, it is just as much a metaphysical assumption to say quantum uncertainty is random as it is to say God controls it.

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  15. "Therefore, it is just as much a metaphysical assumption to say quantum uncertainty is random as it is to say God controls it"

    So you are moving the subject to a metaphysical discussion.
    Are the common ancestor theory relevant from a metaphysical point of view?

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  16. Hi Blas,

    Blas:"So you are moving the subject to a metaphysical discussion."

    Actually it is Dr. Hunter who has moved the subject to a metaphysical discussion. It is the main point of this blog. I was just answering your questions.

    Blas:"Are the common ancestor theory relevant from a metaphysical point of view?"

    I think I have answered my fair share of questions; your turn.

    I have explained to you my hypothesis as to a mechanism that could explain the appearance of common descent which Behe and others claim is well established by the scientific evidence.

    What is your hypothesis for why Chimpanzees, Humans and other ape-like creatures have extremely similar DNA sequences and the same defect in processing Vitamin C?

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  17. "Actually it is Dr. Hunter who has moved the subject to a metaphysical discussion. It is the main point of this blog. I was just answering your questions"

    Seems to me you have got it wrong, Dr Hunters point is Darwinist make metaphisic not science. Keep metaphisics outside science and Dr Hunter has no point.

    "What is your hypothesis for why Chimpanzees, Humans and other ape-like creatures have extremely similar DNA sequences and the same defect in processing Vitamin C?"

    They have similar body building programs, all are survivors of Vitamine C processing loss due his diet rich in vitamine C.


    "Are the common ancestor theory relevant from a metaphysical point of view?"

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  18. Hi Blas,

    Your hypothesis for Vitamin C process seems very close to Lamarck’s theory. However, the modern version (i.e. epigenetics) is only applicable if it isn't due to DNA changes. In this case, we know the lack of Vitamin C processing function is due to a change in the DNA which looks very much like a defect.

    To answer your question...
    I suggest a presumption of "common ancestor theory" is no more metaphysical than a presumption of "gravitational theory". In fact, "common ancestor theory" may be even less metaphysical than "gravitational theory".

    Your turn…
    How metaphysical is your version of Lamarck’s theory as compared to "gravitational theory"?

    ReplyDelete