Reflectorites
I apologise that this is late also.
On Tue, 08 Aug 2000 09:33:44 -0700, Tedd Hadley wrote:
[...]
>SC>Those that did have mechanisms for escaping the new life species would
>>have kept on replicating, and thus the population of predator & prey
>>should have reached some type of equilibrium. This would last until the
>>next development of evolution, in which case the whole process would
>>theoretically repeat itself until a new equilibrium is established.
TH>That's sounds right, but I can't see how this particular situation
>would match anything today. The critical difference is what
>has already been mentioned: life's ubiquity ensures that prebiotic
>elements are quickly eaten.
This was Darwin's excuse back in 1871:
"It is often said that all conditions for the first production of a living
organism are present, which would ever have been present. But if
(and oh, what a big if) we could conceive in some warm little pond,
with all sorts of ammonia and phosphoric salts, light, heat,
electricity etc, present, that a protein compound was chemically
formed ready to undergo still more complex changes, at the present
day such matter would be instantly devoured or absorbed which
would not have been the case before living creatures were formed."
(Darwin C., letter 1871 to Joseph Hooker, in Darwin F., ed, "The
Life and Letters of Charles Darwin", 3 Vols., John Murray:
London, 1888, Vol. 3, p18).
But I wonder how true that assumption is? Even if it was granted
(arguendo) that the earliest bacteria consumed "prebiotic elements" (i.e.
raw amino or nucleic acids or their chemical building blocks), what
evidence is there that *modern day* bacteria consume such "prebiotic
elements" today? Most bacteria today consume the products of existing
biological activity.
There are some highly specialised bacteria which consume some inorganic
products, but none, AFAIK, that consume raw amino or nucleic acids.
So if an amino acid or nucleic acid fragment was produced abiotically
today, what is the *hard scientific evidence* that a bacterium that
exists *today* would consume it?
>SC>So, then, if my logic is not mistaken, evolution does predict that a
>>population of prebiotic molecules should exist in equilibrium with
>>present-day species.
TH>But only as long as there is a life "vaccum", allowing prebiotic
>molecules to exist for lengthy periods of time --maybe years--
>without being broken down into waste products by living organisms
>-- which is nothing like Earth today.
>
>Each square centimeter of your skin averages about 100,000
>bacteria. A single teaspoon of topsoil contains more than
>a billion bacteria. A single gram of sand on the seashore
>contains a billion bacteria. Where can you go on Earth today
>to escape life and still have the conditions for life? No where,
>it would seem.
That might be true in nature but it is not necessarily true in a controlled
artificial setting, like a laboratory.
In my former `life' I was a Hospital Administrator. We had a major hospital
redevelopment which built a new operating theatre for orthopaedic surgery.
I was told that if even one bacterium remained in the site of a bone graft or
hip/knee replacement, then antibiotics would have difficulty reaching it and
the operation would fail, with dire consequences for the patient and the
hospital's malpractice insurance!
But the fact is that such aseptic orthopaedic surgery is routine these days,
so it shows that bacteria-free environments can be routinely produced in
hospitals by modern technology.
Bacteria-free environments are also produced routinely in `clean rooms' in
the computer silicon chip industry. Also labs that do DNA testing must be
free of bacteria, which contain DNA. And when one thinks about it, origin
of life simulations must be able to preserve a bacteria-free environment,
otherwise researchers could never be sure that any signs of life they
observed were produced abiotically, and weren't just remains of bacteria.
But even if one granted that some bacteria would get into an origin of life
experiment where amino acids and/or nucleic acids were present together
in the right conditions for spontaneous self-assembly to occur, it would be
possible to starve the bacteria to death.
This is because:
"All bacteria require carbon, nitrogen, sulfur, phosphorus, inorganic
salts, and micronutrients" (Britannica online.
http://www.britannica.com/bcom/eb/article/1/0,5716,11811+1+11671,00.html).
But all twenty biological amino acids (with two exceptions) are composed
of carbon, hydrogen, oxygen and nitrogen atoms. The two exceptions are
Cysteine and Methionine which have also a sulphur atom. (see chart in
Williams H.J., "Introduction to Organic Chemistry," 1982, pp.178-182).
So an environment that contained only carbon, hydrogen, oxygen and
nitrogen atoms, would be sufficient for amino acids and protein fragments
(polypeptides) to self-assemble, but would be not be life-supporting to
bacteria, because "phosphorus, inorganic salts, and micronutrients" were
absent. Indeed, if sulphur was also absent, only two out of twenty amino
acids could not form.
And the biological nucleic acids DNA and RNA are composed of carbon,
hydrogen, oxygen, nitrogen and phosphorous atoms. (See diagrams in Hale
W.G., & Margham J.P., "Collins Reference Dictionary of Biology," 1988,
p381). So an environment that contained only those elements should be
able to permit self-assembly of nucleic acids, but be not life-supporting to
bacteria, since it lacks "sulfur ... inorganic salts, and micronutrients".
So all one would need to do is create and maintain an artificial environment
with only carbon, hydrogen, oxygen, nitrogen and phosphorous atoms
present and all but two protein, and both nucleic acid fragments should be
able to self-assemble, and no bacteria could survive.
This is so elementary that if it hasn't been done, it would show that origin
of life researchers don't really believe their own excuse!
[...]
On Tue, 08 Aug 2000 10:18:00 -0700, Cliff Lundberg wrote:
[...]
CL>Darwinism doesn't explain the original abiogenesis, it only explains
>the process that abiogenesis began. While ID, as usual, explains
>everything; then, now, and forever.
Cliff should see my post to Richard. He (Cliff) is getting "ID" (i.e. the
*specific* arguments for design espoused by the modern Intelligent Design
Movement) mixed up with the *general* argument from design, as
espoused by Christian apologetics.
While the general argument from design might be hard to falsify (although
Darwinists claim they have done just that in biology), *ID* itself has put
forward some highly specific predictions that can be falsified, such as Mike
Behe's Irreducible Complexity claim, which I here post again:
"It seems then, perhaps counterintuitively to some, that intelligent
design is quite susceptible to falsification, at least on the points
under discussion. Darwinism, on the other hand, seems quite
impervious to falsification. The reason for that can be seen when we
examine the basic claims of the two ideas with regard to a particular
biochemical system like, say, the bacterial flagellum. The claim of
intelligent design is that "No unintelligent process could produce
this system." The claim of Darwinism is that "Some unintelligent
process (involving natural selection and random mutation) could
produce this system." To falsify the first claim, one need only show
that at least one unintelligent process could produce the system. To
falsify the second claim, one would have to show the system could
not have been formed by any of a potentially infinite number of
possible unintelligent processes, which is effectively impossible to
do. I think Professor Coyne and the National Academy of Sciences
have it exactly backwards. A strong point of intelligent design is its
vulnerability to falsification. (Indeed, some of my religious critics
dislike intelligent design theory precisely because they worry that it
will be falsified, and thus theology will appear to suffer another
blow from science. See, for example, (Flietstra 1998).) A weak
point of Darwinian theory is its resistance to falsification. What
experimental evidence could possibly be found that would falsify
the contention that complex molecular machines evolved by a
Darwinian mechanism?" (Behe M.J., "Philosophical Objections to
Intelligent Design: Response to Critics," Discovery Institute July
31, 2000. http://www.discovery.org/embeddedRecentArticles.php3?id=445).
Steve
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"The drawback for scientists is that nature's shrewd economy conceals
enormous complexity. Researchers are finding evidence that the Hox genes
and the non-Hox homeobox genes are not independent agents but members
of vast genetic networks that connect hundreds, perhaps thousands, of
other genes. Change one component, and myriad others will change as
well--and not necessarily for the better. Thus dreams of tinkering with
nature's toolbox to bring to life what scientists call a "hopeful monster"-
such as a fish with feet--are likely to remain elusive." (Nash J.M., "Where
Do Toes Come From?," Time, Vol. 146, No. 5, July 31, 1995.
http://www.time.com/time/magazine/archive/1995/950731/950731.science.html)
Stephen E. Jones | sejones@iinet.net.au | http://www.iinet.net.au/~sejones
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