>-----Original Message-----
>From: asa-owner@lists.calvin.edu [mailto:asa-owner@lists.calvin.edu]On
>Behalf Of george murphy
>Sent: Monday, November 27, 2000 3:04 AM
>To: asa@calvin.edu
>Subject: silicon life?
>
>
> Someone at church today asked me (apropos a discussion of
>anthropic principles) about something he had seen on TV (no explicit
>reference) about tubular structures which had been found at thermal
>vents in the Atlantic & which were supposed to be evidence of silicon
>based life. I don't think that Si-based life has been found (!) but
>have some vague recollection of a news item which might have given rise
>to this report. Can anyone remember such a thing more clearly?
I think this is what you are looking for:
Monday, December 21, 1998 Published at 23:31 GMT
Sci/Tech
Tiny mineral test-tubes: the
cradle of life?
Is it coincidence that bacteria and microscopic mineral pores are
exactly the same size?
The birthplace for life on Earth may have been
labyrinthine networks of tubes on the surface of rocks.
In these natural test tubes, the complex molecules
needed for life could have evolved in safety, taking its
building blocks from the water washing over the rock and
from the minerals within.
New research argues that the pores provide the perfect
sheltered environment for the chain of chemical reactions
necessary to evolve the first bacteria. The proposal, from
scientists at the Universities of Edinburgh and Chicago,
also explains how cell walls first developed: as lids on
the pores used to batten down the hatches during
droughts.
The work was welcomed by Dr Graham Cairns-Smith, an
expert on origin of life at the University of Glasgow. "It's a
fascinating piece of mineralogy and I'm all for it," he told
BBC News Online.
"The idea that the critical organic reactions would take
place in the open primordial oceans is now very hard to
believe."
The new idea follows a painstaking analysis of the microscopic structure of
alkali feldspar, a common mineral in rocks. It solves many of the problems
with current ideas of how life first began.
Life blossoming in primordial pools, rich in organic molecules, is now
thought to be unlikely. The molecules would easily be dispersed by waves or
currents, stopping the chain of reactions. Furthermore, the intense
ultraviolet light shining on the early Earth would have quickly destroyed
any embryonic life.
But a cosy, safe haven would prevent these difficulties. It
has been suggested that clay minerals could have acted
as templates for life.
But as the team leader Professor Ian Parsons at
Edinburgh University told BBC News Online, "That's a
good start but most minerals, including clays, don't work
because they repel rather than attract organic
molecules. However, there is a mineral called zeolite,
one rare type of which does attract organic molecules,
and this could occur on the surface of feldspars."
The first cells
Best of all, the new work presents a plausible way to
develop cell walls, a critical step which allows living
organisms to travel safely in search of food or away from
predators.
Professor Parsons explains: "The reactions for life will
not work in the right order without a container, but you
cannot get a container, or cell wall, until you have the
right reactions - it's Catch 22."
...
http://news.bbc.co.uk/hi/english/sci/tech/newsid_239000/239787.stm
glenn
see http://www.flash.net/~mortongr/dmd.htm
for lots of creation/evolution information
anthropology/geology/paleontology/theology\
personal stories of struggle
>
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