Reflectorites
On Mon, 11 Sep 2000 20:52:17 -0700, Cliff Lundberg wrote:
Sorry again thjis is late but I had already half-answered it!
>SJ>Dr Gunter Wachtershauser, a leading
>>researcher in this field ... [said] the new research was another piece of the
>>jigsaw. "It means you don't need an ocean to create life," he said. "All you
>>need is a little water vapour and a lot of volcanic activity." [If it only
>>takes "a little water vapour and a lot of volcanic activity" why is it so
>hard?
CL>I don't know chemistry, but the root 'pyr' in pyruvic suggests that this
>organic acid has long been associated with high temperatures.
I don't know about the "pyr-" but the "uvic" comes from the
Latin word "uva" meaning "grapes":
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http://m-w.com/cgi-bin/dictionary?book=Dictionary&va=pyruvic ...
pyruvic acid ... Etymology: International Scientific Vocabulary pyr- + Latin
uva grapes; from its importance in fermentation -- more at UVULA ... : a
3-carbon keto acid C3H4O3 that in carbohydrate metabolism is an
important intermediate product formed as pyruvate by glycolysis
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It is a vital link in the Krebs Cycle converting carbohydrates to energy:
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http://m-w.com/cgi-bin/dictionary?book=Dictionary&va=glycolysis ...
glycolysis ... the enzymatic breakdown of a carbohydrate (as glucose) by
way of phosphate derivatives with the production of pyruvic or lactic acid
and energy stored in high-energy phosphate bonds of ATP ...
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CL>Volcanic vents are such small and isolated environments compared to the
>waters of the Earth, and volcanic emissions are so unfriendly to life as we
>know it, it's hard to put much stock in this particular OOL theory.
Agreed. Stanley Miller has said that hydrothermal vents are a major
*problem* to the origin of life because all the ocean water would
eventually pass through a hydrothermal vent and be sterilised of life and life
compounds:
"Stanley Miller and Jeffrey Bada at the University of California at
San Diego have done experiments that suggest the superheated
water inside vents, which sometimes exceeds 572 F, would destroy
rather than create complex organic compounds. As a result, Miller
actually considers the vents a hindrance to the origin of life. Based
on estimates that all of the water in the ocean passes through the
thermal vents each ten million years, Miller has estimated an upper
limit for amino acid concentrations in the ocean to be 3 x 10^-4 M.
Since James Corliss and others agree that current life at the vents
probably migrated there, the thermal-vent origin of life remains a
vague idea, lacking both conceptual details and experimental
support." (Bradley W.L. & Thaxton C.B., "Information & the
Origin of Life," in Moreland J.P., ed., "The Creation Hypothesis,
1994, p.194)
In fact if the temperature inside oceanic hydrothermal vents is 400C (see below),
this is 752F!
CL>The ecosystems that presently inhabit undersea vents are not anaerobic;
>they do indeed metabolize some volcanic emissions, but they live on the
>edge of the anaerobic zone and use oxygen, so they probably weren't
>around before algae put oxygen into the atmosphere.
Agreed. Also the volcanic vents in any one place only last for about 2,000
years, therefore all the thermophiles around them must have migrated
there:
"Evolution of an active sea-floor massive sulphide deposit
Hydrothermal circulation at oceanic spreading ridges causes sea
water to penetrate to depths of 2 to 3km in the oceanic crust where
it is heated to ~400 ĪC before venting at spectacular 'black
smokers'. These hydrothermal systems exert a strong influence on
ocean chemistry, yet their structure, longevity and magnitude
remain largely unresolved. The active Transatlantic Geotraverse
(TAG) deposit, at 26ĪN on the Mid-Atlantic Ridge, is one of the
largest, oldest and most intensively studied of the massive sulphide
mounds that accumulate beneath black-smoker fields. Here the
authors report ages of sulphides and anhydrites from the recently
drilled TAG substrate structures - determined from 234U - 230Th
systematics analysed by thermal ionization mass spectrometry. The
new precise ages combined with existing data show that the oldest
material (11,000 to 37,000 years old) forms a layer across the
centre of the deposit with younger material (2,300-7,800 years old)
both above and below. This stratigraphy confirms that much of the
sulphide and anhydrite are precipitated within the mound by mixing
of entrained sea water with hydrothermal fluid. The age distribution
is consistent with episodic activity of the hydrothermal system
recurring at intervals of up to 2,000 years. C-F You & M J Bickle
Evolution of an active sea-floor massive sulphide deposit (Letter to
Nature) Nature 394, 668 (1998)
Steve
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"The reader may well ask whether, irrespective of the eventual fate of
Darwin's predictions, his teachings have had any direct effect on the later
development of classificatory practice. The answer appears to be, very little
before the end of the nineteenth century, a certain amount in the earlier part
of the present century (at least as far as species are concerned), but very
little again today. ... Curiously enough, one section of the contents of a
recent volume is likely to preserve a recognizable similarity to the
corresponding parts of a century ago- the purely systematic papers. ... the
systematists, alone among mid-Victorian zoologists, would probably find
the works of their present-day successors intelligible. The context suggests
that Darwin expected the revolution to show itself particularly in
systematics, whereas it is precisely this field which has not undergone any
drastic change in the last century. ... In a sense it could be said that the
revolution in systematics had taken place in the century which ended in
1858, that its initiator was Linnaeus (the bicentenary of whose first
employment of the "binomial system" we also celebrate in 1958) and that
Darwin himself was a product rather than a cause of it. Well before the
appearance of the Origin, systematists were seeking for what they already
called a natural system (one that corresponded to the "Plan of Creation")
which Darwin himself equated with his genealogical one, and in their
discussions they used phrases like "closely related to" and "referable to the
same basic type as" which needed only to be taken literally instead of more
or less metaphorically to give them a Darwinian content. So it is
understandable that the acceptance of the theory of evolution made no
great difference to the practice of systematics, and in the decade or two
after 1858 no evident disparity showed itself between the practice of those
systematists who accepted Darwin's doctrine and those who did not."
(Crowson R.A., "Darwin and Classification," in Barnett S.A., ed., "A
Century of Darwin," [1958], Mercury Books: London, 1962, pp.119,121-122).
Stephen E. Jones | sejones@iinet.net.au | http://www.iinet.net.au/~sejones
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