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From: sa209@utb.shv.hb.se (Claes Andersson)
Subject: Re: Lamarckian Evolution -> Crackpot theory
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Date: Sat, 11 Feb 1995 20:26:33 GMT
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dbennett@crl.com (Andrea Chen) wrote:
>shane@reservoir.win-uk.net (Shane McKee) writes:
>
>
>>So what's the point? Barbara McClintock would have been the last
>>to argue for Lamarckian evolution. Evolution in the context of
>>transposable elements is Darwinian all the same, because the
>>information (DNA) doesn't know what the protein does, or whether
>>it's good or bad. Transposons are not a mechanism for Lamarckism.
>
>
>The point of bringing up McClintocks work is quite simple.  It has
>been argued over and over in this thread that there is no known
>mechanism for transferring information from the cell to the genotype.
>In fact there is.  It was established for single cell beings through
>use of the electron microscope and McClintocks work showed that "jumping
>genes" occured in more complex organsisms as well.  Although it is
>still debated whether antibodies are a form of McClintockian transpons,
>we do know (have know for decades) that essentially they are created
>by "random protein generators".  We also have clear knowlege of cybernetic
>structures which control events,  the earliest being Monad and Jacobs
>"operons" with the "structural" and "operater" (which turns on the structural)
>being located one section of the DNA string and "regulator" in an independant
>location.  This simple feedback logic is probaly equivalent to one
>line of code in a huge program (or so I would guess) with layers
>and layers of logics controlling more complex things.  To go on
>with the computer analogy,  transpons provide the equivalent of
>self modifying code.
>
>Now whether transpons are a mechanism for Lamarkism is a matter
>of debate.  I can tell you right off the bat that the example
>given in this thread of giraffes stretching their necks is an
>oversimplification and vulgarization of his this thought. Philosophically
>Darwinism tends to refer to gentotype modification through external
>forces, Lamarckism to refer to a living being modifying itself.  We
>know for a fact (have known for a generation) that it is a two
>way street,  events in the cell can alter the genotype, information
>can flow from the protein (which is what DNA models) complex to the
>DNA complex and the DNA can be modified (transposition is changing
>position,  "jumping genes" is self explanatory).  This is a potential
>mechanism for Lamarckian (if we mean self modifying) life.  It is
>there, it has been known and established for over a generation (thats
>20 years) and still we have people claiming that there is no
>known way for a cell to alter the genetic code.
>
>As for what Barbara McClintock would have said.  She was known to be
>very open minded and since her little ears of corn were altering
>themselves,  one thinks she would be especially open minded on
>this subject.
>
>    - Andrea Chen -

 But still, as I've said several times before, Darwin was comletely right and
Lamarck was completely wrong. Not to say anything bad about him, according
to what they knew then, this was a success since it was the first time that
anyone adressed any form of phenotypic alteration as adaptations to the
envirnoment.

 However, Lamarckism is impossible if you don't believe that some sort of deity
can alter the genome. The idea of Lamarckism as Lamarck inteded it has been
discarded many, meny decades ago for obvious reasons.

 Theories about that there can be a little coding device that lengthens our childrens
legs if we stretch for things often, are crackpot theories that is very simillar to
Velikorsky's (sp?) ideas, creationism etc. Advocates for Lamarckism can expect no
respect for their view whatsoever until they, like any scientist, comes with some
sort of EVIDENCE. Evidence is not to point out that a theory might be correct if
things are in a certain way that there is no reason to expect them to be.

 The reasoning is, for what I've heard here, often based on:
1: There would be an advantage to adapt in a Lamarckistik way and things that are
    to an advantage emerges through evolution.

2: It is impossible to say that there cannot be a little device for encoding traits, it's
    just that we cannot see it or imagine how it works.

3: There are known examples of Lamrackistik evolution.

Okej, comments:

1: Yes it would. But in the same way that the the equations has to be solved once to
    create the solutions book even though it would be more convenient if the solutions
    just were there. This sort of adaptionistic view is easily mathematically disproved.
    A bird would be well off with a jet engine but not with a half one, therefor: no
    jet engine.

2: It is virtually impossible because of that the information in the evolutionary formed
    genome is arranged in a way that is so extremely complex that it is stupid to think that
    an organ smaller than a brain could cope with it. The truth is that this encoder could
    never collect the information at all... What is the correlation between the stretching
    and the lenghtened legs?

3: There are no such examples. There are examples of adaptation but they are still
    Darwinian. It's not too rare that organisms have genes for a certain trait that dwells
    in the genome but seems to be active just sometimes, therefor someone thinks that
    something in, for example the E. Coli, reacts on the lactose and creates a little DNA
   string, inserts it and there you are. This is ofcourse not the case... would it have
    created the samething if you put cyanide there? Or would it have given it legs if it
    found out that it would be good to have them? This is only a form of fast evolution
    that happens quite often (it is an advantage to keep the lactose-gene inactive).


Claes Andersson. University of Bors. Sweden



