Molecular biology ... a crash course or a little help?

Hi guys ... having lumbered myself with a strange argument with an
ID'er over on Yahoo I currently have no response to some claims due to
my woeful lack of knowledge - something I'm sticking my hand up to but
hey, I'm willing to be educated.

I suspect some of the below are knowledge 'boundary' issues - that we
simply don't know. It seems impossible to get said ID proponents to
see that this is not actual evidence of an 'intelligence' however.
It's being put forward for a definitive evidence of the failure of
evolution (not surprsing I know)

There's a lot here so I appreciate if people don't have the
time/inclination, but it would be an education for me if anyone has any
useful links or relevant pointers.

Also the term IC is being thrown around a lot. I suspect it's being
used in double fashion - one as Behe intended, to indicate an
organ/structure that has no naturalistic explanation and also as a
system that is 'irreducible' in the sense that said organ/structure
will fail should an element be removed (but that naturalistic
explanations for why that organ exists are around - the building of an
'archway' analogy). Shoot me down in flames as you please

Thanks

The arguments:

Begin with nucleic acids and note that their
> > > selective value is not dependent on their chemical
> > > composition but rather on their encoding
> > properties.
> > > What natural cause would produce a sequentially
> > > functional arrangement of nucleotides in a
> > prebiotic
> > > soup and how would the encoded information be
> > > translated to functional proteins?

This is followed up with:

I'll add a follow-up. What properties of of
> nucleic acids lead you to believe that their synthesis
> in a prebiotic soup would generate information and an
> encoding convention assuming the synthesis is an
> environmentally viable possibility?



> >Can you really tell me that the entire veracity of ID
> rests
> exclusively on whether we can currently demonstrate
> (or not) the
> origins of the bacterial flagellum?
>
> It does not. You can demonstrate some ability
> to think on your feet and explain how the prokaryotic
> IC transcription and translation function evolved.

I'm not sure what exactly he's asking for here. I can't imagine any
response provided would satisfy him though


A better example of an
> irreducibly
> > complex system that is problematic for a theory
> based
> > on gradual, accumulated, selective changes are the
> > functions necessary for protein synthesis. Before a
> > protein becomes functional the DNA encoding it must
> be
> > transcribed and the resulting mRNA then translated.
> > Numerous cellular components are involved in the
> > process including tRNA, ribosomes and aminoacyl
> > synthetases. A ready supply of amino acids is
> needed
> > some of which are synthesized in metabolic pathways
> > which are dependent on encoded enzymes. This is not
> a
> > system that lends itself to a Darwinian natural
> > selection process.
>
> >You'll have to clarify for me why this does not lend
> itself well to selection/mutation.
>
> Since you have repeatedly asserted evolution
> scientifically explains how systems came to be I'm
> asking you how this specific one came about.

The tendency for DNA helices to form supercoils
> is inherent to the structure; i.e. it stems from
> natural causes. Supercoils form when the DNA strands
> are separated. The strands must separate to enable
> both protein synthesis and the replication of both DNA
> and the cell containing the DNA. A complex of about
> 40 proteins enable organisms to keep supercoiling in
> check through processes that go beyond the scope of
> this thread. Their respective encoding genes are
> found in the DNA itself. How did such an irreducible
> complex system gradually evolve?

.

Relevant Pages

  • Re: Propping up the theory of Evolution
    ... Most selection is selection *against* change. ... to be in the range of 50 or so sites (none a protein coding region). ... DNA is not in a single strand, but divided into 23 chromosomes in the ... Since this is the part under some sequence constraint ...
    (talk.origins)
  • Biochemistry of Genetic Mechanisms
    ... RNA, the same 20 amino acids & ATP) and many identical or nearly ... guanine & cytosine) in DNA. ... protein, acts as a template for the synthesis of RNA in transcription. ...
    (sci.bio.evolution)
  • Re: Propping up the theory of Evolution
    ... selection after a strand of DNA is hit by a cosmic ray. ... DNA and used existing DNA? ... if you mean DNA sequences that do not occur in nature. ... duplication of a 'tool' and modifying the 'working end' so that it ...
    (talk.origins)
  • Re: Primes in DNA (was: Definition Challenge)
    ... That's because they *didn't* find those sorts of statistical anomalies. ... can judge spans of DNA, and rank them according to some metric called ... I already gave you specifics for an encoding mechanism. ... have convinced you that even the most rudimentary statistics make ...
    (talk.origins)
  • Re: Dawkins and natural selection contradicts himself
    ... "....Natural selection, the unconscious, automatic, blind yet ... essentially non-random process that Darwin discovered, ... All life on Earth uses DNA for protein synthesis. ... Sometimes these mutations have an affect on protein synthesis. ...
    (talk.origins)
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