Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!linus!decvax!cca!g-rh
From: g-rh@cca.UUCP (Richard Harter)
Newsgroups: net.misc
Subject: Paper on abiogenesis
Message-ID: <6652@cca.UUCP>
Date: Mon, 6-Feb-84 13:26:01 EST
Article-I.D.: cca.6652
Posted: Mon Feb  6 13:26:01 1984
Date-Received: Thu, 9-Feb-84 04:38:56 EST
Lines: 62


	Recently Paul Dubuc ran a transcription of a paper purporting
to show that abiogenesis was an untenable concept.  More recently he
noted that no one had refuted it.  Per his request, I will attempt to
state what is wrong with the paper.  Unfortunately, I did not save a
copy of the paper, so I am relying on recall.  Also I am not a 
biochemist and do not have the relevant reference material at hand,
so there will be some lack of precision in my comments.

	The paper divides into two parts.  In the first part it is
argued that (a) proteins could not have formed spontaneously out of
water (i.e. on the land or in the air), (b) that in liquid water they
would disassociate, and (c) that they could not form in the presence
of solid or gaseous water.  In the second part, it is argued that
the fact that all proteins are L proteins is highly improbable if
proteins originally formed as a matter of chance.  Amino acids come
in two forms, right (D for dextro), and left (L for levro).  The 
proteins occurring in life are made of either all L amino acids or
all D acids.  D type proteins are very rare.

	Let us dispose of the second argument first.  It is a fact
of biochemistry that the only way proteins can occur is either all
L or all D.  I do not recall off hand the reason -- it may be 
because that is the only way the amino acids will fit together or
it may be a consequence of the mode of construction.  In any case
the calculations presented are irrelevant because they are based
on a false assumption.  The interesting question, which is not
discussed, is why life is left handed rather than a mixture of
left and right handed.  There are two possibilities: (a) all life
is descended from a single left-handed ancestor, or (b) there is
some subtle reason why left handed forms are preferred.

	The first argument was not clear to me.  I am not aware
of any serious proposal that ice or steam played any part in the
formation of life, so I can't judge whether the author was 
introducing a red herring or whether he was quoting something out
of context.  If he was referring to a real proposal, then I feel
sure that he was misrepresenting the proposal -- the points he
raised were obvious ones that any such proposal would have had 
to dealt with.

	His general point that proteins disassociate is well
taken.  In the absence of life organic molecules would build
up in water, but they would also break down.  The equilibrium
point is well below the level of complexity required for life.
There are some concentration mechanisms that have been pro-
posed; however I am not qualified to evaluate them.

	Incidentally, the paper fusses about the notion that
primitive Earth might have had a reducing atmosphere.  As Haldane
pointed out in the 20's, the oxygen in the atmosphere is produced
by and maintained by plant life.  Without life the atmosphere
would either be reducing or neutral, depending on whether there
were significant amounts of methane present.  (The whole matter
is currently under debate in the literature.)

	In short: this paper has a number of errors of logic.
It has other flaws; quoted statements are misrepresented.
Finally:  I am not familiar with Coppredge.  If this paper
is a good example of the reasoning that Coppredge (sp?) uses,
then Coppredge is not worth discussing.
may be a consequence of the w