gjphw@ihuxm.UUCP (02/23/84)
These are a few quick comments about some of the points in the life from
non-living matter discussion. And, yes, I understand that this argument is
peripheral to whether or not evolution occurs for living organisms (i.e., the
infamous creationism/evolution series).
While I am unable to provide a reference (chemistry not being my forte), I
would like to provide support for the view that the primitive Earth possessed
a reducing or neutral atmosphere. In particular, oxygen should be considered
as a fairly reactive gas. Combustion (e.g., fire) is merely the rapid exoth-
ermic reaction of atmospheric oxygen with whatever substance is available to
burn. Living organisms possess elaborate structures (e.g., cell membranes,
skin) to guard against the effects of this poisonous gas. This proclivity of
oxygen to form compounds with a variety of elements would have any free oxygen
on the hot primitive Earth combine with hydrogen to form water and with sili-
con to make silicon dioxide (i.e., rocks). From my readings concerning the
Earth's early atmosphere, the present free oxygen is considered to be a bio-
logical byproduct, life could probably not exist on land without atmospheric
oxygen, and life was comparatively quiescent until living organisms could take
over the land.
Unless I have missed something, and unfortunately I failed to save a copy of
the original article by T. Brown as posted by P. Dubuc, chemistry is not sta-
tistical mechanics. Chemical elements don't form all possible combinations at
random, but rather have preferred combinations. I can only banter about such
phrases as "Gibbs thermodynamic potential" to measure the favorability of any
particular chemical reaction. Using the concept that chemistry is not
entirely random, I think that S. Miller's experiment, and the dozen or so
repetitions of it since the mid-1950's, should be viewed as a demonstration
that the laws of chemistry (whatever those are) do not preclude the formation
of organic macromolecules (e.g., amino acids) from inorganic matter under
"natural" conditions. The continued progression from simple inorganic com-
pounds to more complex organic molecules might even be considered preferred.
There remains a long way to go from this result to the formation of a simple
protein or the lowest virus that resides in me (though the existence of
viruses presupposes higher living organisms or cells), so taking the Miller-
type experiment as a conclusive demonstration for abiogenesis seems unwar-
ranted.
Deriving from the studies of I. Prigogine, and the availability of so called
"supercomputers", there are an increasing number of studies by physicists and
chemists into self-organizing systems. These are systems which, under the
proper conditions, spontaneously increase their order (forming patterns and
decreasing entropy). You might consider these to be simplified models for
living systems. At this point, I can see only two significant characteristics
required for self-organization. The first is that the substance must be non-
linear. Empty space and junk yards are linear media, most common fluids (air
and water) are nonlinear media. The second requirement for self-organization
is an influx of energy (an open thermodynamic system). Under this energy
flux, the entropy over part of the system can decrease at the expense of an
increase in entropy somewhere else. Albert Einstein gave some thought to the
entropy conditions far from equilibrium. Examples of self-organizing
phenomena include solitons and the Earth's weather. If conditions that led to
the spontaneous organization changes, then the pattern may dissipate but usu-
ally persists as long as energetics allow. Abiogenesis would appear to qual-
ify as a self-organizing process, but much more complicated than those
currently under consideration in the studies alluded to above.
With the preceding observations and opinions, we can examine a few points
about abiogenesis. As has been mentioned before by several people, Morris'
arguments against evolution from a thermodynamic perspective omit what is
known or theorized (and idealized) about thermodynamic systems. Of course,
the current emphasis on self-organizing systems and decreasing entropy has
been on the upswing since Prigogine won the Nobel Prize in 1979, and probably
was not prominent to Morris while he was doing the bulk of his writing. How-
ever, T. Brown's criticism and demonstration that life could not arise from
non-living matter is too restrictive to be conclusive. Only the particular
situation where the 14 assumptions of J. Coppedge apply has been considered.
No doubt, those advocating abiogenesis could advance a half dozen mechanisms
that could, in the absence of a laboratory demonstration, lead to living
organisms. On the other hand, critiques of abiogenesis appear to suffer from
the same limitation (absence of laboratory demonstrations).
Most of us have learned about what constitutes proof from mathematics.
Proofs in mathematics and logic are considered to be the paradigm. Unfor-
tunately, mathematics typically follows the logic table for equivalence, while
science obeys the rules for inference. For inference, it is far easier to
establish the falsity of a theory or hypothesis than the truth (assuming that
the predictions derived from the theory have been calculated correctly). From
experience, the debating team for the affirmative (building the case) has a
more difficult task than the team for the negative (critiquing the case). The
only way that a scientific theory can be proven is through the trial of all
possible cases (proof through exhaustion). And, because of the complexity of
most physical systems, an experiment or application provides the superior test
for a body of theories than the axiomatic proofs of mathematics.
The major value of any theory is how it organizes observations or experi-
ments and describes the body of reliable data (thank you, Jay, for reminding
me of this). Even a few discrepancies are not typically judged sufficient to
reject a theory but does hint at the possibility of a better theory. For
example, Newton's Law of Universal Gravitation failed to accurately account
for the motion of Mercury, but was enthusiastically espoused because it
described and unified so many other motions (and opposed because it treated
celestial and terrestrial motions equally). The need for a theory to be
predictive or falsifiable is so that it can be tested (the empirical aspect
that distinguishes science from its parent of natural philosophy).
Brown's argument against abiogenesis criticizes one hypothesis for life
arising from non-living chemicals. It would appear that a conclusive argument
against abiogenesis must exhaust all possible mechanisms (a very time consum-
ing process) while, ironically, support for it could be obtained with a single
demonstration (proof of concept, not proof for the way it must have happened).
I doubt that either possibility can be presented in this newsgroup.
--
Patrick Wyant
AT&T Bell Laboratories (Naperville, IL)
*!ihuxm!gjphw