Junk DNA

Rcjohnsen rcjohnsen at aol.com
Wed Apr 19 22:46:03 EST 2000


<< Subject: Re: Junk DNA
From: iayork at panix.com  (Ian A. York)
Date: Wed, Apr 19, 2000 8:04 PM
Message-id: <8dl3gf$5hm$1 at news.panix.com>

In article <20000419152008.16033.00002300 at ng-ck1.aol.com>,
Rcjohnsen <rcjohnsen at aol.com> wrote:
>
>If you read between the lines of the other posters, Ian, I think you'd see we
>were essentially saying the same thing ie junk DNA is an unfortunate term
>because it lumps DNAs whose functions we do not know--yet.  But if some of
this
>so called junk transposes or moves to a different site which is advantageous
>somehow to the organism and it succeeds in passing this trait to a large part
>of the population, then it is no longer junk/junque but treasure.

But that has nothing to do with the concept.  What bothers people who
learn the term is the concept that DNA can be useless.  Call it junk, call
it repetitive elements, call it what you like, the vast majority of the
genome is most likely useless, the product of random events, not selected.  
And it's that concept that seems to be disturbing the posters on this
thread.

The fortuitous benefit that arises from a fraction of useless DNA becoming
useful is not evidence that the rest of the related DNA was
selected; evolution doesn't work that way, it has no foresight, there's no
mechanism that could generate tons of random DNA in the hope that for
N generations in the future some of it might be useful.  

And if you do claim that the benefit of occasional useful integrations is
some kind of evidence or disproof, you have to account for the more
frequent negative events that are also associated with integrations, and
explain how negative events are functional.

You can't say that being able to make a mobile from discarded tin cans
means the New York garbage dump is useful.

Ian 
-- 
    Ian York   (iayork at panix.com)  <http://www.panix.com/~iayork/>
    "-but as he was a York, I am rather inclined to suppose him a
     very respectable Man." -Jane Austen, The History of England


You can't say that being able to make a mobile from discarded tin cans
means the New York garbage dump is useful.
 >>
I can if I'm an artist.

"Speech and art are the only things that separate us from the animals.  Use
them and savor them fully"
--Carl Sagan   and I'm not even sure that's correct!
Roger





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