Friday, December 24, 2010

The Miracle of Ribosome Assembly Evolution

New research is uncovering the details of how the cell’s protein factory—the ribosome—is constructed. The ribosome translates messenger RNA molecules—edited copies of DNA protein-coding genes—into a string of amino acids, according to the genetic code. The ribosome has two major components (one smaller and one larger), each made up of both RNA and protein molecules, and is constructed via a complex sequence of events.

The RNA components of the ribosome are copies of DNA genes. These ribosomal RNA molecules—known as rRNAs—are initially in a raw copy of DNA which eventually is edited. For instance, one of these copies of DNA may contain many rRNAs, separated by spacer segments. The spacer segments need to be removed, leaving the individual rRNAs ready for assembly.

One of the findings of the new research is that in the early stages of assembly, one of the DNA copies folds up such that a spacer segment binds to one of the rRNAs. In particular, the spacer binds to the special segment of the rRNA that reads the messenger RNA molecules, in the final, assembled ribosome. When the spacer is removed, the rRNA switches to its correct shape, for function in the ribosome. One implication of this finding is that ribosome construction can be regulated by this switch. Remove the spacer and ribosome construction proceeds. Leave the spacer, and ribosome construction halts. As the researchers concluded:

our data show that the intrinsic ability of RNA to form stable structural switches is exploited to order and regulate RNA-dependent biological processes.

RNA tends to fold up into a variety of shapes. In this case, as lead researcher Katrin Karbstein suggests, RNA folding properties are part of the design:

Perhaps, nature has found a way to exploit RNA’s Achilles’ heel—its propensity to form alternative structures … Nature might be using this to stall important biological processes and allow for quality control and regulation.

But of course this mechanism brings yet more complexity:

What is interesting is that as the organism becomes more complex, the number of cleavages needed increases. This may make the process more accurate and that may be an evolutionary advantage, but even in bacteria this cutting is not done in a simple way. We still don’t know exactly why that is.

Karbstein suggests that the strictly ordered cutting and pasting steps in ribosome assembly are introduced to produce singularly perfect intermediates. As she explains:

Ribosomes make mistakes rarely, on the order of one in 10,000 amino acid changes. A lot of this accuracy depends on conversations between different parts of the ribosomes, so if the structure of the RNA isn’t correct, these conversations can’t happen. And that means more mistakes, and that’s not good because it can lead to any number of disease states.

Ribosomes don’t just happen. They are not easily assembled and the evolution of this choreography calls for several just-so heroics. Yes, this fine-tuned set of mechanisms makes for fantastic regulation of the cellular protein making factory, but it means that evolution must have gone through a stage where life didn’t work. For the spacer segment that binds to the rRNA is a show-stopper. It would be selected against instantly.

The only way to resolve this problem is to have the spacer removal mechanism already in place, before the spacer sequence itself evolved. As usual, evolutionists would need to rely on the needed mechanism just happening to serve some other useful purpose, and when the spacer sequence happened to arise for no reason, the removal mechanism found new work for itself. In other words, mutations arose that caused the DNA copy to fold, rendering ribosome synthesis—and life itself—impossible. But as luck would have it, there just happened to be the right molecular machine lying around that removed the problematic segment at just the right time and place. Not only was the fatal flaw obviated, but a brilliant new means of regulation invented. Amazing. Over time, further mutations happened to refine its actions and today we have the fine-tuned ribosome assembly process.

There you have it—evolution’s just-add-water version of science. For the umpteenth time evolution becomes a charade. Behind the scenes, in deep-time where no one can see it working, evolution once again performs miracle after miracle.

8 comments:

  1. Dr. Hunter, it seems apparent that Darwinian evolutionists actually do believe in miracles, they just refuse to believe in the miracle maker!!!

    ReplyDelete
  2. Cornelius,
    "The only way to resolve this problem is to have the spacer removal mechanism already in place, before the spacer sequence itself evolved. As usual, evolutionists rely on the needed mechanism just happening to serve some other useful purpose, and when the spacer sequence happened to arise for no reason, the removal mechanism found new work for itself."

    is this your own take on what evolutionists would say, or what they actually have said? in other words, did you just make this up? a simple yes or no will suffice.

    ReplyDelete
  3. Come on, people, a miracle is an unexpected event attributed to the intervention of God.

    Are you saying that whenever we encounter an unexplained phenomenon, we have to immediately attribute its origin to a special action of God?

    Wouldn't that be silly?

    ReplyDelete
  4. Gary said:

    Darwhiners know nothing of engineering and nothing of statistical mechanics, combinatorial dependencies or logic.

    Darwieners are immune to logic.


    Gary, you're in trouble:

    Santa Claus is coming to town
    He's making a list
    And checking it twice;
    Gonna find out Who's naughty and nice
    Santa Claus is coming to town
    He sees you when you're sleeping
    He knows when you're awake
    He knows if you've been bad or good
    So be good for goodness sake!

    ReplyDelete
  5. nanobot74:

    ===
    Cornelius,
    "The only way to resolve this problem ..."

    is this your own take on what evolutionists would say, or what they actually have said? in other words, did you just make this up? a simple yes or no will suffice.
    ===

    Both. This pre adaptation is standard fare for evolutionists. In this particular case no explanation was given beyond vague tautologies such as "nature might be using this ...", "nature exploited RNA folding properties," etc. So the standard evolutionary explanation I gave is certainly typical, but I had to provide it. My imagination is certainly not that of an evolutionists, so I'm glad to insert whatever evolutionists dream up outside the usual pre adaptation story.

    ReplyDelete
  6. Gary the yappy little puppy said...

    Miracles are denied by materialists but truly miraculous biological events are not! Doh!

    Worse, the author said, "and allow for quality control and regulation."!

    QA control in bio systems?!
    Duh.

    Yes folks, this is an accidental miracle like every other miracle in the Darwinian fantasy.

    I can already hear the inevitable "CH doesn't understand evolution" and "nor entropy nor probabilities have anything to do with bio systems", utter bull shit responses.

    Darwhiners know nothing of engineering and nothing of statistical mechanics, combinatorial dependencies or logic.

    Darwieners are immune to logic.


    Merry Kitzman there you yappy little puppy!

    It sure was hilarious watching you pee on yourself and run away when your bluff on statistical mechanics got called.

    So keep going yip yip yip yip! while we laugh at your cowardice and ignorance.

    ReplyDelete
  7. Pedand said,

    Santa Claus is coming to town
    He's making a list
    And checking it twice;
    Gonna find out Who's naughty and nice
    Santa Claus is coming to town
    He sees you when you're sleeping
    He knows when you're awake
    He knows if you've been bad or good
    So be good for goodness sake!

    Compare that with the rock hard science of Origin of Species, CDarwin,

    "Natural selection is daily and hourly scrutinising, throughout the world, every variation, even the slightest...daily and hourly scrutinizing...rejecting
    what is bad and preserving and adding up all that is good."

    Some misguided creationists attempt to misinterpret this and to say that the central mechanism of evolution is as a Fairy Godmother or Santa --which actively intervenes and contradicts natural laws millions of times each day. That the use of terms like "good" shows preplanning and teleology. And that, while evolutionists complain of a God demonstrating initial Intelligent Design, yet in CDarwin an anthropocentric "mystical hand" actively intervenes in nature countless times each day. They are wrong, though, and that was all corrected in the 3rd edition of ORIGIN when CDarwin inserted the word "metaphorically" (scrutinizing).

    ReplyDelete
  8. Dear Mr Thorton. Rather than excreting the same ad hominems that most evos do. Please provide SUBSTANCE to your claims with evidence, rather than mouthing of like a bag of wind. Mr Hunter has given his evidence, the least you can do, (to preserve YOUR intellectual honesty), is to provide evidence for your claims.

    Lest you assume that whatever you say is absolute and hence needs nothing to verify it, (I wouldn't be surprised, most evos are like that).

    ReplyDelete