Upon closely examining his arguments in this debate, it seems clear that John Patterson is using thermodynamic arguments that have no relevance to the origin of life.
By way of background, one may write the equation for the Gibbs free energy change that accompanies aqueous chemical reactions or phase changes as follows (including only terms of significance):
where the change in enthalpy (
H) is principally
due to the change in bonding energy that occurs during the chemical
reaction or phase change, the change in thermal entropy (-Sth)
describes the change in the number of ways the thermal energy
can be arranged in the system, and the change in configurational
entropy ( cont) is associated with the change in the number
of ways the mass can be arranged in the system. The Second Law
of Thermodynamics requires that the change in the Gibbs free energy
be negative for reactions that occur spontaneously (i.e., do not
require some external energetic driving force).
When water freezes, when alloys experience diffusion up a concentration
gradient (as they do during spinodal decomposition), or when atomic
oxygen becomes molecular oxygen, (the three examples alluded to
by Patterson) there is a decrease in entropy in the system. This
is easily explained by the fact that change in enthalpy in each
of these cases (and in many others one could cite) is negative
(H less than 0): i.e., the reaction is exothermic.
The energy released to the surrounding gives a sufficient increase
in entropy to compensate for the local decrease in entropy, giving
a net increase in the entropy of the universe as required by the
Second Law of Thermodynamics.
One can illustrate this local ordering process by picturing a pool table on which someone has dropped a steel ball, one foot in diameter, producing a hemispherical depression in the very center of the table but leaving the rest of the table flat (see Fig. 1). Furthermore, assume that paper has been stuffed in each of the pockets to prevent the loss of balls from the table via the pockets, and picture the table being gently agitated randomly in the horizontal plane to maintain constant movement of the pool balls. You would hardly be surprised to find in due course that all of the balls would end up in a very nonrandom arrangement; namely, in the hemispherical depression in the center of the table. In the absence of such a hole, the probability of ever finding all of the balls within a one foot diameter circle at the center of the table can be calculated to be less than 1/10 exp20. Thus, an otherwise extremely improbable event becomes essentially certain when there is a local potential well.
It should then be emphasized that keeping all the balls in
the hole would require that the agitation of the table be gentle.
If the table were agitated more violently, all of the balls would
not remain in the hole. The agitation of the table illustrates
the thermal agitation present in real systems. For example, water
will form the very orderly arrangement of molecules in ice (illustrated
by the pool balls in a hole in the center of the table) as long
as the thermal agitation of the system (illustrated by the agitation
of the table) does not exceed some critical value (which it does
at the melting point). Again the formation of ice is possible
because H = -80cal/gram (1.44Kcal/mole) when water freezes.
What, if any, significance do the formation of snowflakes,
spinodal decomposition, or the formation of molecular oxygen from
atomic oxygen (which was the key illustration in the paper referred
to by Patterson, Thermodynamics: The Red Herring, by Hugo
F. Franzen) have to do with the crucial condenstation polymerization
reactions required in the Oparian paradigm of the origin of life
for the formation of protein and DNA? When one recognizes that
the change in enthalpy (H) for such chemical reaction
is positive, it is quite clear that such illustrations have no
relevance to the origin of life.
We might illustrate this by returning to our original example
of a pool table (see Fig. 2). The difficulty
in getting polymerization condensation reactions is that our pool
table is neither flat (H=0), nor does it have a hole
(H less than 0). Rather it has a hill (H greater
than 0). Morowitz [1]
in his classic Energy Flow in Biology indicates that the
macromolecule formation required to produce a living system in
general has a H=+16.4 cal/gm. He further notes that the net increase
in bonding energy in going from simple compounds to E. Coli
bacterium is 0.27ev/atom. Thaxton, Bradley and Olsen
[2] using data from Hutchens
[3] calculate an enthalpy increase of 5-8Kcal/mole
for the formation of dipeptide from amino acids (combining two
amino acids). One might conclude that the formation of protein
and DNA via polymerization condensation reactions is well nigh
impossible. With regard to this issue of the formation of macromolecules
near equilibrium, Prigogine et al. [4]
have noted "The probability that at ordinary temperatures
a macroscopic number of molecules is assembled to give rise to
the highly ordered structures and to the coordinated functions
characterizing living organisms is vanishingly small. The idea
of spontaneous genesis of life in its present form is therefore
highly improbable, even on the scale of billions of years during
which prebiotic evolution occurred." Thus, the idea of a
self ordering system implicit in the analogies of Patterson and
others is seen to be irrelevant.
The only solution to this dilemma is to do some very specific work on the system to assist these balls up the hill. It should be added that this work must be very carefully done so as to not jar loose the balls that are already there. Thus, the energy must be selective in getting the balls up the hill while at the same time not causing the balls there to be removed from their positions of metastable equilibrium. Beyond this, the balls must be arranged in very specific sequencing of monomers in polymers to give biological function.
With regard to this problem of the energy flow through the system and its adequacy to do the required work, Nicolis and Prigogine [5] have noted, "Needless to say, these simple remarks cannot suffice to solve the problem of biological order. One would like not only to establish that the second law is compatible with a decrease in overall entropy, but also to indicate the mechanisms responsible for the emergence and maintenance of coherent states." To be more specific, the question is, "How can energy flow through the system which generates negative thermal entropy be coupled to do the required negative configurational entropy work; i.e., how can we convert energy flow into information?" Prigogine at al. [4] makes much more modest claims about the significance of their work in this regard than Patterson implies, using such expressions as "one is tempted to hope" that their work on dissipative structures will someday be found to be significant in answering these questions.
It is interesting to note that Patterson spends all of his time criticizing the work of creationists without making any attempt to use his own thermodynamic training to address the very significant problems outlined above. His position seems to be that if we can show some creationists make mistakes in their thermodynamic arguments, there are no thermodynamic problems. I find this to be an odd position, given that many scientists who share Patterson's conviction that the origin of life was naturalistic readily admit to the problems mentioned above [6]. In fact the question of how to generate the requisite complexity is universally recognized as the core problem in the origin of life. To show that some creationists may overstate or misrepresent the problem is hardly a substitute for a scientific solution to the problem.
Finally, it is interesting that in all of Patterson's writings I have yet to find any reference to the work of Thaxton, Bradley and Olsen [2]. Patterson and I have corresponded in the past with regard to his book, his failure to address the issues raised in this volume cannot be atrributed to ignorance about its contents. I thus find it difficult not to wonder about Patterson's own motives in this debate. I should add that Cramer [7], to whom Patterson has referred as a creationist who believes there are no thermodynamic problems with the origin of life, has since changed his mind after reading our book.
I do not believe that anyone has done the kind of thermodynamic analysis required to determine whether the Second Law of Thermodynamics represents any significant obstacle to biological evolution. Again, the kind of analysis we did in our book for the origin of life would be useful to quantify the nature and magnitude of the work required for macroevolution and the suitibility of the available energy and structures to do this work. It is certainly a question that should be pursued.
Arduini's comments reflect a lack of awareness of our book in which a decrease in configurational entropy is clearly quantified for the current paradigm for the origin of life. However, for a plausible naturalistic origin of life scenario to be established, it must be explained how energy flow through the system can be coupled to do the required work. Furthermore, his assertions with regard to Wilder-Smith should be qualified as follows: Wilder-Smith was only referring to biological evolution. In both of his books The Creation of Life and Man's Origin, Man's Destiny, he clearly argues that there are significant thermodynamic problems with the origin of life. He does not say that the Second Law of Thermodynamics precludes it but notes as we did in our book that the conversion of energy flow into information remains, at present, undemonstrated and without theoretical basis.
Walter L. Bradley received his Ph.D. in materials science from the University of Texas. He has participated as principal or co-principal investigator on over a million dollars of contract research, and has consulted for several major corporations. The author of over 30 research papers (published in refereed journals), he has held the Texas Engineering Experimental Station Research Fellowship since 1982 and is professor of Mechanical Engineering at Texas A&M University. He is also co-author of the 1984 book The Mystery of Life's Origin: Reassessing Current Theories. In this article, he directly addresses some of the arguments raised by John Patterson and Francis Arduini. He also addresses, in a more direct fashion, some of the concerns raised by our other writers.
Copyright © 1997 Walter L. Bradley. All
rights reserved. International copyright secured.
File Date: 3.13.97