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[...]
Like all messages, the life message is non-material but has
an information content measurable in bits and bytes and plays
the role, ascribed by vitalists, of an unmeasurable,
metaphysical vital force without being _ad hoc_, romantic,
spooky, contrary to the laws of physics or supernatural.
Of course, like all messages, the genetic message, although
non-material, must be recorded in matter or energy.
Scientists, throughout the world, are busy sequencing the
human genome and the genomes of other organisms and
recording them in computer hard drives, the information
capacity of which is measured in bits and bytes. These
genetic messages '..._contain all the biologically meaningful
aspects of genetic information that represent the purposeful
organization (sic) of living cells and organisms_.' Whose
_purpose_ is it? Information can be measured; science must
concern itself with what can be measured and leave subjective
concepts like _meaning_ and _purpose_ to philosophers and
theologians.
The genetic logic system must be capable of accomodating
the genetic messages of all organisms that have ever lived,
live now, or will be evolved in the future. The DNA sequences
that make up the genome of any organism are _selected from a
set_ of possible messages. As Schrodinger had pointed out
previously, the number of such sequences is transcomputational
in magnitude and provides more than ample capacity to record
the complexity of living organisms. Thus the biological
information system or genetic logic system is independent of
the specificity or meaning of the genetic message in the
genome. All communication systems will process meaningless
noise as well as a play by Sophocles.
[...]
_Origin of Life_
Lifson accuses me of '..._flogging all theories and scenarios
of the origin of life by the whip of algorithmic information
theory._' To this charge of heresy I gladly plead guilty.
In a previous publication, Lifson said: '_In setting the
scene for transition from inanimate to animate matter, one
must take for granted the existence of a prebiotic world
where multitudes of various chemical compounds interact
with each other in all possible ways according to the laws
of chemistry and physics, continuously forming and breaking
structures that contain covalent bonds, ion complexes, as well
as weak interactions such as hydrogen bonds. Also granted is
an electromagnetic source of solar energy that catalyses
various reactions by creating free radicals and other forms
of excited molecules_.'
Thus Lifson supports the standard model of the origin of
life, usually attributed to the Lysenkoist, Oparin. Both
the standard model of the origin of life and the self-
organizationalist speculations of Manfred Eigen, Stuart
Kauffman and Sidney Fox require, _in extremis_ to their
views, a primeval soup in the early ocean.
Would there not be geological evidence in rocks of 4 to
3.8 billion years old, if there had been such a soup?
The space science studies board believes there should be:
'_These speculations on chemical evolution, multiple
origins of life, and models of early environmental
conditions in the atmosphere and oceans can only be
substantiated by the geological record_.' What testimony
would have been left behind by the primeval soup in the
sedimentary rocks? We can learn this directly from the
work of those scientists who take the primeval soup for
granted. All methods of simulating the formation of
amino acids and other 'building blocks' leave a tarry
polymeric material as their most abundant product. Carbon
that was once composed of living matter is slightly
enriched in 12^C. No chemical reaction, heat, pressure
or other treatment to which these ancient rocks may have
been subjected can change one of these isotopes to
another. Thus the carbon isotope ratio is a reliable and
indestructable fingerprint to determine whether carbonaceous
material, including kerogen, came from living organisms
or by inorganic chemistry from a primordial carbon source.
Sedimentary rocks at Isua in Greenland have been dated at
3.8 billion years ago, a time near the end of the late
heavy bombardment. They do indeed contain kerogen.
Schidlowski reported that all carbon in these rocks divides
distinctly into two groups, one high in 13^C and one depleted
in 13^C, with respect to the isotope ratio found in
atmospheric carbon dioxide. The kerogen of the very old
Isua rocks is depleted in 13^C. This is just what would
be expected if the kerogen had been derived from cyano-
bacteria-like microorganisms capable of photosynthesis
of carbon dioxide and nitrogen by means of an enzyme
system to form living matter.
According to the standard model for the origin of life,
there are two paths the carbon would follow in the
primeval soup. The first is toward forming the ancient
protobiont, the remains of which would go to kerogen.
The second, and the much more abundant amount, is the
tarry material generated in all origin-of-life simulation
experiments. No kerogen from the tarry material left over
from the generation of the 'building blocks' of life is
found. This is extremely good confirmation that there
never were the large quantities of dissolved amino acids,
or other 'building blocks', that could be called a primeval
soup. The significance of the very old kerogen in the Isua
rocks in Greenland is that there never was a primeval soup
and that living matter must have existed abundantly on Earth
before 3.8 billion years ago.
Even the true believers Stanley Miller and Carl Sagan have
estimated an extremely dilute primeval soup. Miller's latest
(1992) estimate of the concentration of the primeval soup
is 0.0003 M. Chyba and Sagan estimated the concentration of
organic compounds in the primeval ocean as 0.1% if the
atmosphere had been reducing (it was not), or 0.0001% if it
had been neutral (it was). That is as far as a true believer
has gone towards admitting that no primeval soup ever existed.
So much for prebiotic synthesis of organic compounds and
chemical evolution! _The absence of evidence is evidence of
absence_!
Lifson complains that I commit _lese majeste_ by ridiculing
Eigen and Schuster as well as Dawkins by comparing them to
the savants at the Grand Academy of Lagado in Jonathan
Swift's _Gulliver's Travels_. Proceeding with 'origin-of-life
research' without first establishing geological evidence that
a primeval soup existed at one time in the Earth's history
reminds one of the ingenious architect in the Grand Academy
of Lagado, who had contrived a new method of building houses
by beginning at the roof and working down so that he
contemplated completing the foundation last. Although this
idea had been approved by peer review, it was still in the
research stage and he had not yet put it into practice.
The architect pointed out that among the advantages of this
procedure was that once the roof was in place the rest of
the construction could proceed quickly and without interruption
by weather.
It is amusing to note that the ridicule Jonathan Swift heaped
on the Grand Academy of Lagado, and indirectly on those in his
time, is abundantly justified for all origin-of-life scenarios
or theories based on a primeval soup that never existed.
Eigen's hypercycles are moot; there were no self-organizing
autocatalytic molecules to grow exponentially. The same
restriction applies to RNA-world and any other theory of
the origin of life based on dialectical materialism.
There is not enough space in this letter to discuss other
issues brought up by Lifson. I suggest that those who are
not committed to an ideology read _Information Theory and
Molecular Biology_ and decide its merits for themselves.
-- H.P. Yockey, "Information in bits and bytes",
_BioEssays_, vol. 17, no. 1, 1995, pp. 85-88.
[This is a letter in reply to S. Lifson,
"What is Information for Molecular Biology",
_BioEssays_, vol. 16, no. 5, 1995, pp. 373-375]
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Brian Harper |
Associate Professor | "It is not certain that all is uncertain,
Applied Mechanics | to the glory of skepticism" -- Pascal
Ohio State University |
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