Re: DNA growth... Where and how does this happen?

MicroTech wrote:
> I have scoured countless web pages and read all kinds of books on
> evolution, genetics, bio/organic chemistry etc etc, but nowhere can I
> find any references to WHERE in the human system "new" base pairs are
> added to the mighty DNA double helix, or what triggers the addition of
> such new "code". Closely related is the question on which DNA that is
> used as the "Master" molecule to be copied into the sperm/egg
> chromosomes: would this not be the only place where "random
> mutations" could occur?
>
> It seems obvious to me that, on the long and winding path from the
> first prokaryote DNA to my own personal genome, there has been many new
> base pairs added over the 3 500 000 000 or so years since the process
> started (AFASK). Opinions differ on the size of the human genome, but
> there seems to be an informal consensus around the value 3 500 000 000
> (nucleotide base pairs)-neat coincidence, an average of one new base
> pair per year!
>
> I am *not* a creationist (rather, an agnostic, in the true sense of the
> word). I firmly believe that Darwin is on to something in his "On the
> Origin of Species." However, I find it more than difficult to envision
> how "random mutations" (caused by cosmic rays or other radioactivity?)
> or replication errors could lead to something as immensely complex as
> Life... at least in such a short time span as 3.6 billion years. Some
> additional mechanism must, somehow, be at play here, no?
>
> If someone in this group could lead me to where I can read about actual
> "DNA building and genome growth"-is it something like the
> high-growth tip of a plant root?-it would be very much appreciated!
>
> Thanks,
>
> Henry Norman
> www.microtechnonstop.com
>
>

To cut to the chase look up "gene duplication". I believe this is the
mechanism most responsible for increasing the size of genomes. Gene
duplication followed by mutation and selection on the duplicated genes.
In plants there is the phenomenon of entire chromosome duplication.


--dkomo@xxxxxxxx


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Relevant Pages

  • Re: Gaps in the fossil record.
    ... mutations are deleterious and fatal to organisms? ... support the duplication, degeneration and complementation model for gene ... "Nothing supporting my assertions there." ...
    (talk.origins)
  • Re: Re: Gaps in the fossil record.
    ... support the duplication, degeneration and complementation model for gene ... nothing about the deleterious effects of mutations. ... Gene duplication is often cited as a potential mechanism for the ...
    (talk.origins)
  • Re: BBC the creationist at the museum
    ... proof that information increases in the genome. ... A mutation that changes a gene can be ... Gene duplication is a fairly common type of mutation. ...
    (talk.origins)
  • Re: BBC the creationist at the museum
    ... proof that information increases in the genome. ... A mutation that changes a gene can be ... Gene duplication is a fairly common type of mutation. ...
    (talk.origins)
  • Re: Gaps in the fossil record.
    ... support the duplication, degeneration and complementation model for gene ... nothing about the deleterious effects of mutations. ... Gene duplication is often cited as a potential mechanism for the ...
    (talk.origins)
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