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From: mrh@cybvax0.UUCP (Mike Huybensz)
Newsgroups: net.origins
Subject: Re: Mutations
Message-ID: <486@cybvax0.UUCP>
Date: Mon, 22-Apr-85 16:13:49 EST
Article-I.D.: cybvax0.486
Posted: Mon Apr 22 16:13:49 1985
Date-Received: Thu, 25-Apr-85 08:16:36 EST
References: <942@uwmacc.UUCP>
Reply-To: mrh@cybvax0.UUCP (Mike Huybensz)
Distribution: net
Organization: Cybermation, Inc., Cambridge, MA
Lines: 77
Summary: 

In article <942@uwmacc.UUCP> dubois@uwmacc.UUCP (Paul DuBois) writes:
> Pierre Grasse', "Evolution of Living Organisms:  Evidence for a New
> Theory of Transformation".  Academic Press, New York, 1977.
> 
>   "Some contemporary biologists, as soon as they observe a mutation,
> talk about evolution.  They are implicitly supporting the following
> syllogism:  mutations are the only evolutionary variations, all living
> beings undergo mutations, therefore living things evolve.
>   "This logical scheme is, however unacceptable:  first, because its
> major premise is neither obvious nor general; second, because its
> conclusion does not agree with the facts.  No matter how numerous they
> may be, mutations do not produce any kind of evolution.

Grasse' is correct here, in the same sense that wood does not produce a
house.  Mutations are thought to be the raw material of evolution:
recombination and selection compose the actual process.

However, his syllogism is a straw horse.  Partly because of the distinctions
between microevolution and macroevolution.

>   "We add that it would be all too easy to object that mutations have
> no evolutionary effect because they are eliminated by natural
> selection.  [Note that this is exactly the role natural selection plays
> according to many creationists - pd]  Lethal mutations (the worst kind)
> are effectively eliminated, but others persist as alleles.  The human
> species provides a great many examples of this, e.g., the color of the
> eyes, the shape of the auricle, dermatoglyphics, the color and texture
> of the hair, the pigmentation of the skin.  Mutants are present within
> every population, from bacteria to man.  There can be no doubt about
> it.  But for the evolutionist, the essential lies elsewhere:  in the
> fact that mutations do not coincide with evolution."  [p88]

Population genetics has explained for decades that mutations (excepting
dominant lethals) are NOT eliminated from populations: they are maintained
at a relatively constant low level.  This is the idea of genetic load
(for harmful mutations.)

> (Note to Mike Huybensz:  the above is the answer to your question "what
> did he say?" that you posted in response to the citation of Grasse' in
> one of the "Case for Creation" articles.)

And as can be seen from the above, it certainly doesn't refute evolution
nor support creationism.

> Earlier he says regarding bacteria:  "Bacteria, the study of which has
> formed a great part of the foundation of genetics and molecular
> theory, are the organisms which, because of their huge numbers, produce
> the most mutants ... The bacillus _Escherichia coli_, whose mutants
> have been studied very carefully, is the best example.  The reader
> will agree that it is surprising, to say the least, to want to prove
> evolution and to discover its mechanisms and then to choose as a
> material for this study a being which practically stabilized a billion
> years ago!

Why will I agree?  The choice of bacteria was made because (pragmatically)
they have relatively simple genetic systems with fewer variables, and
thus are easier to experiment upon.  It would be foolish to experiment ONLY
on them: but this hasn't happened.  And the mechanisms discovered have been
confirmed in eucaryotic organisms as well.

The information discovered also reveals that bacteria have not "stabilized":
they are in constant genetic flux, exchanging chromosomal material through
viruses and sex.

>   "What is the use of their unceasing mutations if they do not change?
> In sum, the mutations of bacteria and viruses are merely hereditary
> fluctuations around a median position; a swing to the right, a swing
> to the left, but no final evolutionary effect."  [p87]

How does he know they do not change?  How would they refrain from mutating?

The idea of fluctuations around a local optimum is an important one for
explaining stability of species, but overlooks the possibility of new
and changing environments providing new local optimums.
-- 

Mike Huybensz		...decvax!genrad!mit-eddie!cybvax0!mrh