First let me say that I did not intend my previous comments as
a criticism of science in general, scientists in general or
even origin of life researchers in general, but rather those
individuals who accept and promote as a fact that the earth's
early oceans contained a primordial soup.
You say that the soup is but one possibility. I am curious which
origin of life scenarios do not require a soup in the earth's early
oceans. Only two that I know of, Cairns-Smith's clay mineral scenario
and the hydrothermal vent scenario, and both of these are highly
speculative. But I think even these require the soup. At some point
CS's clay life will have to serve as some sort of template or
something to bridge the gap to organic life. Where do the organic
compounds come from and on what do the first critters subsist until
some type of metabolism evolves? Same problem for the
hydrothermal vent creatures when they leave home to take over the
oceans. The soup seems to be the goo that holds all origin of
life scenarios together. Somewhere along the line they all seem to
need it, if only as a source of building blocks or food.
Above you wrote:
>Pim> But the experiments are not to show how it happened as much as
>that it could have happened.
This seems to me an odd statement. The origin of life on earth
would seem to me to be an established fact. We are confident
that life has not always existed on earth. We are almost as
confident :) that it exists now. So I think everyone would
agree that it could happen ;-).
Of course, what you are getting at I guess is that it could
have happened in a particular way. But what is gained by
showing it could have happenned a particular way if that
particular way requires a primordial soup and there is no
evidence that that soup ever existed?
>Pim>With respect to c) I can understand why you believe there are good reasons
>and evidence to say that it did not exist but without knowing what you are
>refering to the statement has little scientific relevance.
>
Ok, let me briefly outline the reasons (from memory, so some
details may be a little off):
1) The modern scientific view is that the earth's early atmosphere
was at most very mildly reducing and more likely neutral.
2) Miller experiments in these type atmospheres yield only small
amounts of amino acids, at least two orders less than in reducing
atmospheres. Just as importantly, but not as widely recognized,
the *variety* of amino acids is also greatly reduced. If I
remember correctly, only one in other than trace amounts.
3) Relatively rapid circulation of the earths early oceans through
hydrothermal vents would have destroyed what little organics
formed.
4) Meteorite impacts would have made the origin of life impossible
for the first few hundred million years. This impact frustration
subsided to the point where life might form about 3.8 to 4.1
billion years ago. Yet life was well established on Earth
about 3.8 billion years ago. You have at most a few hundred
million years.
5) There is no abiotic carbon in 3.8 million year old rock
samples (the soup vanished without a trace).
>Pim>
>"But this is beside the point, which was that Gould for some reason
>thinks he can use a theological argument when it suits him but will
>not allow Paul the same priveledge."
>
>My remarks that appeal to supernatural has little scientific relevance
>stands irregardless of Gould's remarks. It only serves to apply double.
>
On this we agree, but this isn't quite what you said originally ;-).
Brian Harper
Associate Professor
Applied Mechanics
The Ohio State University
"Should I refuse a good dinner simply because I
do not understand the process of digestion?"
-- Oliver Heaviside