On Sun, 15 Jun 2003 22:21:36 +0000 (UTC), ragland10000{at}aol.com
(Michael Ragland) wrote:

>r norman  wrote in message
news:...
>> On Sat, 14 Jun 2003 17:03:13 +0000 (UTC), ragland37{at}webtv.net (Michael
>> Ragland) wrote:
>> 

>> The simple fact is that the genetic code is NOT universal though it is
>> very close.  There are differences especially in mitochondrial DNA and
>> in a variety of cilate protists.  It is certainly theoretically
>> possibly  to modify the code and I have even heard serious scientific
>> talk of ways to genetically engineer small modifications as
>> experimental tools to help elucidate some details of molecular
>> biology. For example, a novel amino acid could be introduced into the
>> system by modifying one (or a very few) transfer RNAs. However, any
>> overall tampering with the code, swapping one codon for another for
>> example, would immediately break the entire system.  
>> 
>> Unfortunately, the notion that "aggression is related to the universal
>> genetic code" is really quite uninformative.  If there are, indeed
>> genes for "aggression", then it is because these genes
produce protein
>> products that are involved in specific signaling systems in specific
>> nervous pathways in the brain, or that are involved in controlling
>> specific patterns of neuronal development and connectivity in specific
>> nervous patheways in the brain.  The nature of the genetic code is
>> irrelevant.  How proteins function is everything. That is why, now
>> that we "know" the human genome, we really know very little and
>> attention is changing from genomics to proteomics.
>
>  Response:
>  I agree with you stating aggression is related to the standard
>genetic code
>  is uninformative. I'm sure you're aware there are many unanswered
>scientific
>  questions regarding the standard genetic code e.g. how it came
>about,its
>  evolution, how it is related to the "message". We may have some of
>the answers
>  but there is an awful lot we don't know. I think it is presumptious
>to state
>  the nature of the genetic code is irrelevant. Yes, swapping one
>codon for
>  another would break down the system. But I'm not suggesting today,
>fifty, or
>  one-hundred years from now that be be done. Science progresses
>incrementally.
>  We will learn things in the future we didn't before and some of
>those things
>  will overturn our previous scientific theories and "beliefs."
>Obviously, how
>  proteins function is important. I would not say they are
>"everything". I
>  don't see attention changing from genomics to proteomics. We've just
>recently
>  completed the Human Genome Project and this is just the very bare
>basics.
>  To use an analogy its as if we removed a cover to see the genes and
>now we
>  we will have to discover the functions of these genes.
>
>  I think many people are scared because all of this is "uncharted
>territory"
>  and it leads to the possibility of genetically engineering humans.
>But when
>  I look at the current "evolution" of Homo Sapiens I will not be shy
>in saying
>  I welcome such future developments, however problematical they
>should be.
>  Below is an article entitled "DNA Double Helix". It contains false
>statements.
>  The reason I want you to read it because its premise is the genetic
>code
>  refutes any theory of evolution. (Note to Moderator: The below
>article is from
>  a Creationist website but I'm including it here to juxtapose it to
>scientists
>  such as Larry Moran and Mr. Norman who make statements such as "the
>genetic
>  code can't be changed" and "the genetic code is irrelevant". Mr.
>Moran and
>  Mr. Norman may think science establishs this and the Creationists
>would most
>  likely heartily agree. I recognize Mr. Moran and Mr. Norman doesn't
>believe
>  the genetic code refutes any theory of evolution but the point I'm
>making is
>  Creationists are using the statements of scientists such as Mr.
>Moran and
>  Mr. Norman that the genetic code can't be changed and is irrelevant
>to
>  propagandize their case evolution doesn't exist. Given that science
>is a
>  continued process of learning I think it would be best to refrain
>from making
>  statements "the genetic code can't be changed" and "the genetic
>code" is
>  irrelevant, especially when coming from scientists. If you think
>that state
>  it as your opinion and not as a "scientific fact".
>


I still think you are not understanding the situation properly.

Although people do speculate about just how the specific genetic code
that is almost universal came to be, the fact is that the specific
sequence of DNA is of very little functional significance.  Almost
everything that happens inside the cell is the result of protein
action and it is the sequence of amino acids in the protein that
counts.  Yes, there are functional RNAs and, yes, much current
thinking is that there was an earlier RNA world that predated our
current protein world in which RNAs played a (or the) major functional
role as catalysts and structural elements. Still, the significance of
the genetic code for modern cells is almost entirely the amino acid
sequence that results from the selective transcription and splicing of
functional genes.  Presumably, a parallel universe with a completely
different genetic code, but with all the appropriate changes made in
the DNA sequence so that exactly the same proteins were transcribed in
the same manner and with the same transcriptional regulation would
function essentially the same as our own universe.  That is why I say
that the genetic code is irrelevant.

Of course the code can mutate and change and evolve.  How do you think
all those alternative codes came into being?  And I already cited
speculation on creating modifications of the code with genetic
engineering.  It is not fixed and immutable!  However, nature can
really no longer do any significant tinkering with it for eukaryotic
nuclear genes because such an elaborate system has been built around
the existing code. So Larry Moran can say that the code "can't" be
changed even knowing all of this.

When we scientists use all the technical jargon and hedges necessary
to describe all the intricate details at work in the natural world and
still account for all the exceptions, we are accused of being
incapable of communicating with the lay audience.  Then, when we
simplify and explain things in ordinary language, perhaps
oversimplifying a bit for the sake of illustration and clarity, we get
our statements taken out of context and applied literally and as
absolute scientific dogma.  I can't help what creationists do with my
statements -- they are perfectly capable of misinterpreting and
twisting words to their purposes in any event.  

Michael, you use a very nice metaphor to say "we removed a cover to
see the genes and now we  we will have to discover the functions of
these genes."  What you are saying, specifically, is that we have to
turn our attention from genomics to proteomics!  I say that
categorically now.  In a few decades (or a few years), we may discover
that the "silent" and "junk" and
"non-transcribed" regions of DNA
really do have a major functional role in the cell.  When that
happens, I'll change my tune.  That is the way science works.  We
change with the times. But the smart money, for the time being at
least, is with the proteins.
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