[2005/08/05] Origin of Life: Can A Liability Be Turned Into an Asset?
Origin of Life: Can A Liability Be Turned Into an Asset?
08/05/2005 Most
of us know the Second Law of Thermodynamics (2TD) as the law of decay and
disorder, and would tend to assume it would constitute a major obstacle to
theories of the origin of life by chemical evolution; certainly
creationists Duane Gish and Henry Morris frequently employed the 2TD
skilfully in their debates with evolutionists. Surprisingly, Eric
Schneider and Dorian Sagan (Carl Sagan¡¯s son by his first wife, the Gaia
theorist Lynn Margulis) praised the 2TD as a life-giving principle in
their new book, Into the Cool: Energy Flow, Thermodynamics and
Life. ¡°Cool is not enough¡± remarked J. Doyne Farmer (Santa Fe
Institute) in his review of the book in Nature.1
Unimpressed with the concept, he smirked, ¡°There¡¯s more to life than the
second law of thermodynamics.¡± How could Schneider and
Dorian Sagan turn a liability like 2TD into an asset? Farmer gives
their thesis a two-paragraph synopsis:
The authors¡¯ central thesis is that
the broad principle needed to understand self-organization is already
implicit in the second law of thermodynamics, and so has been
right under our noses for a century and a half. Although
the second law is a statement about increasing disorder, they
argue that recent generalizations in non-equilibrium thermodynamics make
it clear that it also plays a central role in creating
order. The catchphrase they use to summarize this idea
is ¡°nature abhors a gradient¡±. Being out of equilibrium
automatically implies a gradient in the flow of energy from free energy
to heat. For example, an organism takes in food, which provides
the free energy needed to do work to perform its activities, maintain
its form and reproduce. The conversion of free energy to entropy
goes hand in hand with the maintenance of organization in living
systems. The twist is to claim that the need to
reduce energy gradients drives a tendency towards increasing
complexity in both living and non-living systems. In their
words: ¡°Even before natural selection, the second law
¡®selects¡¯, from the kinetic, thermodynamic, and chemical options
available, those systems best able to reduce gradients under given
constraints.¡± For example, they argue that the reason a climax
forest replaces an earlier transition forest is that it is more
efficient at fixing energy from the Sun, which also reduces the
temperature gradient. They claim that the competition to reduce
gradients introduces a force for selection, in which less effective
mechanisms to reduce gradients are replaced by more effective
ones. They argue that this is the fundamental reason why both
living and non-living systems tend to display higher levels of
organization over time [sic]. (Emphasis added in all
quotes.)
Interesting, Farmer mumbles, but uh-uh. ¡°This
is an intriguing idea but I am not convinced that it makes sense.¡±
He proceeds to criticize their vagueness of the ¡°selection¡± process or why
things should tend to increase in complexity. Yes, the 2TD is
important for understanding the operation of complex systems, but ¡°the
authors¡¯ claim that non-equilibrium thermodynamics explains just about
everything falls flat,¡± he contends. For example, ¡°consider a
computer.¡± A computer has a power supply, but ¡°the need for power
tells us nothing about what makes a laptop different from a washing
machine.¡± At this point, things get interesting. Farmer starts
arguing intelligent design; is this J. Doyne Farmer speaking, or Stephen
Meyer?
To understand how a computer
works, and what it can and cannot do, requires the
theory of computation, which is a logical theory that is
disconnected from thermodynamics. The power supply can be
designed by the same person who designs them for washing
machines. The key point is that, although the second
law is necessary for the emergence of complex order, it is far
from sufficient. Life is inherently an
out-of-equilibrium phenomenon, but then so is an
explosion. Something other than nonequilibrium thermodynamics
is needed to explain why these are fundamentally different.
Life relies on the ability of matter to store information and to
implement functional relationships, which allow organisms to maintain
their form and execute purposeful behaviours that enhance their
survival. Such complex order depends on the rules by
which matter interacts. It may well be that many of the details
are not important, and that there are general principles that might
allow us to determine when the result will be organization and when it
will be chaos. But this cannot be understood in terms of
thermodynamics alone.
With this, Farmer left the
origin of life as an unsolved problem. ¡°Understanding the logical
and physical principles that provide sufficient conditions for life is a
fascinating and difficult problem that should keep scientists busy for at
least a millennium,¡± he wrote. Thermodynamics is just one of many
actors in the play, and not even the principal one; ¡°The others remain
unknown.¡±
1J. Doyne Farmer, ¡°Cool is not enough,¡± Nature
436, 627-628 (4 August 2005) | doi: 10.1038/436627a.
They¡¯re not unknown; they¡¯re right in
your hotel room drawer. This review was interesting because Farmer
invoked arguments similar to those used by creationists and intelligent
design theorists. Since it is highly doubtful that Farmer¡¯s review
was religiously motivated, this supports the contention that arguments
against chemical evolution arise from the facts, not the
motivation. Contrary to the habits of their opponents,
Morris and Gish always stuck to the scientific principles and
observational facts, not theological arguments, in their famous debates
on college campuses with leading evolutionists. Like Farmer, they
stressed that energy is necessary, but not sufficient, for life or for
any other directed process that uses energy to accomplish work.
They argued that two other principles always need to be applied: (1) an
energy conversion mechanism, and (2) a program to direct the energy
toward the desired end. In an automobile, for instance, the
chemical energy of the gasoline is converted into kinetic energy of the
drive shaft by channeling the ¡°explosion¡± of the fuel in the piston
according to a programmed sequence of events: inlet, spark, explosion
against the moveable piston, outlet for the waste gases and heat,
etc. In a plant leaf, the energy of sunlight is directed into very
complex conversion mechanisms of photosynthesis to direct it into
metabolic processes. Gish always emphasized that the
application of raw energy is even more harmful than none at all: pouring
gas on the car and lighting a match does not help it drive uphill, and
holding a dead stick up to the sunlight will not make it sprout and grow
fruit. Only when the far-from-equilibrium energy is channeled by
intelligent design will the tendency toward disorder be overcome, and
that only locally and temporarily. The downhill effects of the
Second Law of Thermodynamics are inexorable; all real processes must
obey the law of entropy. In this book review, Farmer admitted as
much, and even made the case stronger by pointing to computers. A
laptop computer channels electrical energy into complex programmed
pathways that we all know are the result of intelligent design.
Software engineers may be far from equilibrium, but there¡¯s more to the
story than that! That Schneider and Dorian Sagan would
try to turn the Second Law into a driving force for evolution is almost
comical. The Big Science establishment treats Gaia theory, even
its most naturalistic incarnations, with nearly the same disdain as it
does creationism. Nature would not let this book get by
with any more than faint praise for some aspects, but that they would
let the reviewer employ implicit ID/creationist reasoning to debunk its
primary thesis is instructive.