Glenn wrote:
At 08:46 AM 3/2/96, you wrote:
>The Mistake
>
>I made a big mistake the other day at work. I checked the reflector
>archives.
I knew you would ;-).
>I saw Eddie Olmstead's mistaken post which should have gone to the
>ASA. Then I saw that Brian replied to the Eddie post. Well, I couldn't
>resist this, like an addict can't resist narcotics.
>
I am like Glenn in being unable to resist this particular topic :-).
At the time of my former reply I had not seen Glenn's entire post
to the ASA reflector, only those sections contained in Eddie's
response that ended up here. What I saw there was very similar
to what Glenn had written here, so I assumed that Glenn was still
discussing what I referred to as the "chance scenario". As I
indicated earlier, there are many scenarios for the origin of
life. All will involve both chance and determinism at least to
some degree. When I say "chance scenario" I'm talking about what
was the first scenario for the origin of life. This is a proteins
first scenario that is dominated by chance. Entire proteins form
due to chance encounters in the primordial soup. I hadn't realized
Glenn was dealing now with the RNA World scenario. As I said
previously, I think this is a much better direction since it
greatly reduces the role of chance.
So, perhaps I jumped the gun a little and misunderstood Glenn's
intent. Since our last "meeting" I had improved my probability
calculations, generalizing them to the language analogy, so
I couldn't resist the opportunity to present them.
Glenn:=========================
>I want to make clear that I was NOT, repeat NOT talking about the "primordial
>soup". In fact the article I cited in my original post to ASA was Eklund,
>Szostak and Bartel, "Structurally Complex and Highly Active RNA Ligases
>Derived from Random RNA sequences." Science v 269, July 21, 1995, p 364-370
>This article is applicable to the RNA world not to the primordial soup.
> The mathematics I presented here is applicable to proteins, DNA and to the
>RNA world. Any map of functionality over sequence space is going to have the
>properties I used in my discussion. Brian,I don't know why you think the
>math I presented is not applicable to the RNA world. RNA is a polymer, has
>various lengths of sequences which perform a given function and have a
>multiple sequence =>function map.
>
I have looked over this article and a few others related to it. I think
this work goes a long way toward showing that the formation of a
replicating RNA is very reasonable.
Well, I really hate to be too agreeable :). I think that the RNA
world has a lot going for it, its most serious difficulty being
how it got started in the first place. Joyce and Orgel have
written an excellent article summarizing the various difficulties
involved in the origin of the RNA World
Gerald Joyce and Leslie Orgel, "Prospects for Understanding the
Origin of the RNA World", _The RNA World_, Cold Spring Harbor
Laboratory Press, 1993, pp. 1-25.
They discuss many things here including the error catastrophe that
I mentioned previously. I anticipate that this may be a crucial
aspect for the RNA first scenario. Here I want to center in on another
item:
In our initial discussion of the RNA world we accept
The Molecular Biologist's Dream: "Once upon a time there
was a prebiotic pool full of (Beta)-D-nucleotides... ."
We now consider what would have to have happened to make
the dream come true. This discussion triggers The Prebiotic
Chemist's Nightmare: how to make any kind of self-replicating
system from the kind of intractable mixture that is formed
in experiments designed to simulate the chemistry of the
primitive earth.
-- Joyce and Orgel, "Prospects for Understanding the
Origin of the RNA World", _The RNA World_, Cold Spring Harbor
Laboratory Press, 1993, pp. 1-25.
Here, of course, I am entering my protest to Glenn's statement that
he is not talking about the primordial soup. The primordial soup is
not a separate origin of life scenario but rather a necessary ingredient
shared by almost all scenarios. A lot of pre-biotic chemistry must
go on before one gets the "Molecular Biologist's Dream". How this is
obtained takes one back to orthodox soup theory.
Let me give another example. Stanley Miller's recent paper:
Robertson, M.P. and S.L. Miller. "An Efficient Prebiotic
Synthesis of Cytosine and Uracil," <Nature>
v. 375(29 June 1995):772-774.
has been considered a big boost for the RNA World scenario in providing
a prebiotic synthesis for two of the RNA bases. In discussing this paper
in _Science News_, Lipkin wrote:
At some time more than 3 billion years ago, nucleic acids
formed in the primordial soup that simmered on primitive
Earth. These large molecules, notably RNA and DNA, evolved
into the genetic basis of life.
-- R. Lipkin, "Early Earth may have had two key RNA bases",
_Science News_, vol. 148:7, July 1995.
At present, although not often discussed, the RNA World requires
a primordial soup. It is possible that one might get an RNA World
without a soup, the most likely choice being the deep sea hydrothermal
vents. It is important to note , however, that switching from soup to vent
carries certain consequences. One can't just cavalierly say: "OK,
it happened in a vent". Most of the pre-biotic syntheses require
a soup. No matter how nice the chemistry of Miller's synthesis
above, if the origin of life occurred in a vent then the synthesis
is irrelevant. Perhaps this is one reason that many resist moving
the origin of life to vents. A lot of work will have to be repeated
under realistic vent conditions.
This also illustrates the (IMHO) suitableness of Yockey's seemingly
harsh comparison of many origin of life researchers with the architect
at the Grand Academy of Lagado (Gulliver's Travels) who sought to
build houses by starting at the roof and working down to the foundation.
The roof would, of course, be the RNA World and the foundation would
be the soup. No matter how nice the roof, it will fall without the
foundation :).
Glenn:====
>Now, you say you do not want to go back to the dark days of chance. You use
>chance in a very funny way. Self-organizational systems are operated by
>stochastic means e.g. Sierpinski's Gasket and I believe evolution.
Hopefully its clearer now what I meant by the "dark days of chance".
Although I can't seem to resist getting into discussions on abiogenesis,
I always seem to get myself into an uncomfortable position where I
end up arguing against both "sides". It really irks me when I see
someone trying to sweep the problems under the rug (I'm not referring
to Glenn here, BTW). For example, on talk.origins its common to see
something like: "There are so many scenarios for the origin of life,
the real problem is trying to decide which one is correct." Based on
present knowledge this should read: "There are so many scenarios for
the origin of life, unfortunately none of them work." ;-). It is also
disturbing to see the way origin of life research is presented at
the popular level. But its hard for me to blame the scientists working
in this field for this. All the various difficulties with origin
of life scenarios are openly discussed in the literature.
But it also disturbs me to see simplistic probability calculations
presented as if they refute the possibility of abiogenesis in
general rather than a specific scenario for abiogenesis. This topic
is currently being discussed on talk.origins where someone came up
with the following (excellent) analogy [names removed to protect the
guilty ;-)]
[###] is rather like a man who has claimed that no
bridge can be built across a certain river. He has
then calculated that a particular type of bridge,
ill suited to the task of spanning this river could
not be built to do the job, and offered that as proof
that the river cannot be bridged at all. His argument
doesn't do the job, nor does it leave him with any
cards in his hand at all.
Below I'll give a quote from Owen Gingerich's excellent article
"Dare a Scientist Believe in Design". This article has had a
tremendous impact on me and I find myself agreeing with Owen
more and more. I realize that what Owen says here will be
controversial, I include this so that people may have a little
better idea where I'm coming from:
Several years ago I participated in a remarkable conference
of theists and atheists in Dallas. One session considered the
origin of life, and a group of Christian biochemists argued
that the historical record was nonscientific since it was
impossible to perform scientific experiments on history.
Furthermore, they amassed considerable evidence that the
current scenarios of the chemical evolution of life were
untenable. One of the atheists aligned against them, Professor
Clifford Matthews from the University of Chicago, conceded that
their criticisms had considerable validity. Calling their book
on _The Mystery of Life's Origin_ brilliant, he summarized
their arguments with respect to the standard picture of chemical
evolution as saying, "(1) the evidence is weak, (2) the premises
are wrong, and (3) the whole thing is impossible."
I soon found myself in the somewhat anomalous position that to
me, the atheists' approach was much more interesting than the
theists'. That particular group of Christian biochemists had
concluded that ordinary science did not work in such a historical
situation, that is, with respect to the origin of life, and they
attempted to delineate an alternative "origin science" in which
the explicit guiding hand of God could make possible what was
otherwise beyond any probability. The reason I admired the atheist
biochemists so much was that they had not given up. They were
still proposing ingeneous avenues whereby catalytic effects in
the chemistry made the events far more likely. "Let us not flee
to a supernaturalistic explanation," they said, let us not retreat
from the laboratory."
Now it might be that the chemistry of life's origins _is_ forever
beyond human comprehension, but I see no way to establish that
scientifically. Therefore it seems to me to be part of science
to keep trying, even if ultimately there is no accessible answer.
Am I contradicting myself to say, on the one hand, that the resonance
levels in carbon and oxygen point to a superintelligent design,
and on the other hand, that science must continue to search for
underlying reasons why the resonance levels are that way and not
some other way? I think not, for even if it is shown that those
levels had to be the way they are because of some fundamental,
invariable reason, there is still the miracle of design that led
it so, choice or not. Therefore, I see no reason that an appreciation
of the astonishing details of design should prevent us from trying
to search further into their underlying causes. Hence I am not
prepared to concede that arguments from design are necessarily
contrascientific in nature.
Perhaps part of Provine's outrage came because he was responding
to Phillip Johnson, professor of law at Berkeley, who is an
articulate legal champion of the right to believe in God as
Creator and Designer, and a critic of an evolutionary process
running entirely by chance. Earlier I mentioned the incredible
odds calculated by Lecomte du Nouy against the chance formation
of a protein molecule. Since we do have proteins, and since a
mechanistic science has been highly successful, the overwhelming
reaction has just been to ignore du Nouy, since he is so obviously
wrong. But is he? For science to overcome the odds, it is necessary
to for us to postulate catalysts and unknown pathways to make the
formation of life from inert matter enormously easier, and it is of
course precisely such pathways that are the challenge of science
to find. But is not the existence of such pathways also evidence
of design? And are they not inevitable? That is what materialists
such as Provine do not want to hear, but as Hoyle says, the numbers
one calculates put the matter beyond question.
So, while I differ from those Christian biochemists who postulate
some new kind of "origin science," I do think a science totally
devoid of the idea of design may be in danger of running into a
blank wall. And this brings me to ask again, is the idea of design
a threat to science? and I answer no, perhaps design might even be
a necessary ingredient in science.
-- Owen Gingerich, "Dare a Scientist Believe in Design,"
_Evidence of Purpose: Scientists Discover the Creator_,
J.M. Templeton, ed., Continuum, NY, 1994, pp. 30-31.
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Brian Harper |
Associate Professor | "It is not certain that all is uncertain,
Applied Mechanics | to the glory of skepticism" -- Pascal
Ohio State University |
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