Reflectorites
On Fri, 18 Aug 2000 09:58:38 -0700, Tedd Hadley wrote:
[...]
>SJ>1) do we know that these "putrefactive bacteria" have always been around
>>from the beginning cleaning up any "amino and nucleic acids" produced?
TH>We know bacteria are among the oldest life forms known, so its
>a pretty good assumption.
So it is only an "assumption"? We don't *know* (i.e. there is no
actual *evidence* that "putrefactive bacteria" have always been around?
>SJ>2) are they anerobic, since there was presumably little or no
>>oxygen around for the first billion years? and
TH>Very likely, most (all?) putrefactive bacteria are anerobic.
If "putrefactive bacteria are anerobic" how do they live in the gut which has
air in it?
>SJ>3) since there were no "intestines" around for the first billion
>>years or so, do these "putrefactive bacteria break down amino
>>and nucleic acids" out in the *outside world* in a completely
>>abiotic setting?
TH>First, the putrefactive bacteria are pretty much everywhere,
>not just in the human intestinal tract, since decaying plant or
>animal matter is found pretty much everywhere.
What is the evidence that *modern day* bacteria consume raw amino and
nucleic acids that are produced *non-biologically*?
I would have thought that 4 billion years later, with such a vast quantity of
"decaying plant or animal matter" available, bacteria might have specialised
to only go after "decaying plant or animal matter", not the small quantities
of amino or nucleic acids produced abiotically?
I should point out that this bacteria question is not a major issue with me,
but I am still interested in seeing the answers.
TH>However, four
>billion years ago, who knows? Maybe the first life form
>thrived on a soup of life precursors.
What "soup" would that be exactly?:
"And then what of the 'primitive soup' required for Chemical
Evolution? If such an environment ever existed on Planet Earth for
any appreciable time, it would require relatively large quantities of
nitrogen-containing organic compounds (amino-acids, nucleic acid
bases and so on). It is likely that such nitrogen-rich soups would
have given significant quantities of ' nitrogenous cokes', trapped in
various PreCambrian sediments. (The formation of such 'cokes' is
the normal result obtained by heating organic matter rich in
nitrogenous substances.) No such nitrogen-rich materials have yet
been found in early PreCambrian rocks on this planet In fact the
opposite seems to be true: the nitrogen content of early
PreCambrian organic matter is relatively low (less than 0.15%).
From this we can be reasonably certain that: * there never was any
substantial amount of 'primitive soup' on Earth when ancient
PreCambrian sediments were formed; * if such a 'soup' ever existed
it was only for a brief period of time. Subtract from the basic
concept of the Chemical Evolution Theory the ideas of substantial
amounts of 'primitive soup' and a long period of time, and there is
very little left." (Brooks J., "Origins of Life," Lion: Tring,
Hertfordshire UK, 1985, p.118)
[...]
>SJ>Even here I am not convinced. A complete mirror image D-amino acid life
>>form could emerge and existing bacteria might not be able to eat it?
TH>That I don't know. It's been postulated that intrinsic properties
>of L make it required for life.
No doubt. But what *evidence* is there of it though? As I understand it
both the L- and D- biological amino acids are chemically identical.
[...]
>SJ>Tedd makes it sound like it is new. In fact a "abiogenesis research" has
>>been "taking place" in laboratories since at least *1953*, i.e. 47 years
>>(!) and no life has yet emerged spontaneously.
TH>Well, gosh, medical research has been going on since the *1800*s,
>i.e. 200 years (!) and we still can't cure the common cold.
My understanding is that "the common cold" is actually a syndrome of
about *200* different strains of virii:
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http://www.britannica.com/bcom/eb/article/4/0,5716,25374+1+24968,00.html
... ENCYCLOPAEDIA BRITANNICA common cold a viral infection that starts in
the upper respiratory tract, sometimes spreads to the lower structures,
and may contribute secondary infections in the eyes or middle ears. The
main differences between the common cold and other respiratory infections
are the absence of fever and the relative mildness of the symptoms.
About 200 different strains of virus are capable of producing colds.
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and it is not that it cannot be cured, but that it is not worth the
resources and the constant vaccinations required to do it. Influenza is
caused by similar virii:
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http://www.britannica.com/bcom/eb/article/6/0,5716,55956+1+54588,00.html
... ENCYCLOPAEDIA BRITANNICA myxovirus any of a group of viruses of the
families Orthomyxoviridae (agents of influenza) and Paramyxoviridae,
members of which can cause the common cold, mumps, and measles in humans,
canine distemper, rinderpest in cattle, and Newcastle disease in fowl.
The virus particle is enveloped in a fatty membrane; is variable in shape,
from spheroidal to filamentous, and in size, from 60 to 300 nanometres
(1 nanometre = 10-9 metre) in longest dimension; is studded with spikelike
protein projections; and contains ribonucleic acid (RNA). These viruses
react with mucin (mucoprotein) on the surface of red blood cells (hence
the prefix myxo-, Greek for "mucin"); many of them cause red cells to
clump together (agglutinate). Compare retrovirus.
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but there are less strains of it and it is more severe:
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http://www.britannica.com/bcom/eb/article/1/0,5716,43351+1+42398,00.h
tml ... ENCYCLOPAEDIA BRITANNICA influenza also called GRIPPE,
OR FLU, an acute viral infection of the upper or lower respiratory tracts
that is marked by fever, chills, and a generalized feeling of weakness and
pain in muscles, together with varying signs of soreness in the respiratory
tract, head, and abdomen. Influenza is caused by any of several strains of
myxoviruses, categorized as types A, B, and C. The type A virus is the
most frequent cause of influenza; this type occurs in numerous strains that
are clinically differentiated on the basis of the viruses' surface proteins,
their geographic origin, date of isolation, and other factors. The major
types of influenza viruses generally produce similar symptoms but are
completely unrelated antigenically, so that infection with one type confers
no immunity against another.
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so it is worth the resources in wealthy countries to prevent it by
vaccination.
TH>I guess we ought to give up know and just conclude God created
>Viral Rhinitis to make life difficult for us? :)
In the case of the virii (and most scientific problems), generally the case has
been that as science's knowledge has increased, the solution to the
problems become apparent, even though in some cases (like the common
cold) it also became apparent that the resources required to solve the
problem was not warranted by the cost.
But in the case of the origin of life, the problem is not that we don't know
enough, but that we now know *too much*:
"Notice, however, that the sharp edge of this critique is not what
we *do not* know, but what we *do* know. Many facts have
come to light in the past three decades of experimental inquiry into
life's beginning. With each passing year the criticism has gotten
stronger. The advance of science itself is what is challenging the
nation that life arose on earth by spontaneous (in a thermodynamic
sense) chemical reactions.Over the years a slowly emerging line or
boundary has appeared which shows observationally the limits of
what can be expected from matter and energy left to themselves,
and what can be accomplished only through what Michael Polanyi
has called "a profoundly informative intervention." When it is
acknowledged that most so-called prebiotic simulation experiments
actually owe their success to the crucial but *illegitimate* role of
the investigator, a new and fresh phase of the experimental
approach to life's origin can then be entered. Until then however,
the literature of chemical evolution will probably continue to be
dominated by reports of experiments in which the investigator, like
a metabolizing Maxwell Demon, will have performed work on the
system through intelligent, exogenous intervention. Such work
establishes experimental boundary conditions, and imposes
intelligent influence/control over a supposedly "prebiotic" earth. As
long as this informative interference of the investigator is ignored,
the illusion of prebiotic simulation will be fostered. We would
predict that this practice will prove to be a barrier to solving the
mystery of life's origin." (Thaxton C.B., Bradley W.L. & Olsen
R.L., "The Mystery of Life's Origin," 1992, Second Printing, p.185.
Emphasis in original).
>SJ>For a fraction of the cost of sending a mission to Mars to see if life
>>spontaneously generated there when conditions were once right, every
>>conceivable set of such condition could be repeated on Earth in a laboratory
>>and hey presto! life should emerge.
TH>No, I hardly think so. There's too many possible conditions to
>duplicate. Take all supposed or surmised elements of prebiotic
>earth, combine with all known or surmised conditions and you're
>going to need a laboratory the *size of Earth*. You seriously
>overestimate the amount of knowledge we have in this area.
Not really. If they think that life can form on the early Earth, Mars or
Europa, then they are already tacitly admitting a fairly narrow range of
temperature, pressure, chemicals, radiation, etc. For example, amino and
nucleic acids cannot survive above a certain temperature and radiation
level. Water is only liquid between 0-100 degrees C.
Forty-seven years of actually trying to simulate abiogenesis must have
given researchers a lot of information on what the parameters are within
which abiogenesis can and cannot occur.
And there must be *thousands* of labs on Earth which could each try
varying one parameter, while keeping others constant. By eliminating blind
alleys and sharing results, they should be able to converge on the solution
eventually.
In fact that is probably what they *have* been doing these last 47 years and
have got nowhere!
[...]
Steve
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"It is hard to resist the impression of something - some influence capable of
transcending spacetime and the confinements of relativistic causality -
possessing an overview of the entire cosmos at the instant of its creation,
and manipulating all the causally disconnected parts to go bang with almost
exactly the same vigour at the same time, and yet not so exactly
Coordinated as to preclude the small scale, slight irregularities that
eventually formed the galaxies, and us." (Davies P.C.W., "The Accidental
Universe," [1982], Cambridge University Press: Cambridge UK, 1983,
reprint, p.95)
Stephen E. Jones | sejones@iinet.net.au | http://www.iinet.net.au/~sejones
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