Science in Christian Perspective
I. DO LIFE PROCESSES TRANSCEND PHYSICS AND CHEMISTRY?
From: JASA 22 (December 1970): 125-127.
This is the title of one of the general symposia of the AAAS meeting on December 30, 1967, the transcript of which was published in Zygon 3, 442 (1968). Participants in the symposium were Gerald Holton, Chairman, Professor of Physics at Harvard University; Michael Polanyi, Professor of Physical Chemistry at Victoria University at Manchester, England, from 1933 to 1948, and then Professor of Social Sciences; Ernest Nagel, University Professor at Columbia University; John R. Platt, Research Biophysicist and Associate Director of the Mental Health Research Institute of the University of Michigan; and Barry Commoner, Chairman of the Department of Botany and Director of the Center for the Biology of Natural Systems at Washington University in St. Louis. This distinguished panel addressed itself to the question of the title. In view of the article by Dr. Polanyi published in this issue of the Journal ASA, we shall not repeat his perspective here, but will concentrate instead on the contributions of the other members of the panel.
Nagel argued principally that the question could not be decisively answered, maintaining that the impossibility of reducing biology to physics and chemistry was a position that could not be conclusively established. In order to answer the question posed in the title, it is necessary to know what theory of physics and chemistry is in mind as the basis of the explanation. Although it may not be possible to reduce biological phenomena to presently known theories of physics and chemistry, who is to say what the future might bring? The issue is an empirical one, not one to be solved by abstract philosophical cogitation.
Nagel also emphasized two other points of relevance. (1) The observation that terms exist in laws at a higher level that do not exist in laws at a lower level cannot be used as conclusive evidence that the laws at a higher level cannot he explained by laws at a lower one. (2) Two questions must be kept separate: whether it is possible to give a physicochemical explanation of biological laws as they relate to biological organisms at the present, and whether it is possible to give a physicochemical explanation of the laws involved in the historical or evolutionary development of biological organisms. Nagel feels that it is quite possible that the answer is yes to the first of these questions, and no to the second.
Platt answered an emphatic, "Yes," to the question of the title. His reasons fall into three categories. (1) Ordinary analysis from the "objective" point of view. Emergent properties"systems properties"characterize biological systems with increasing size and complexity, and systems properties are not easily predictable from the properties of the subsystems. Can one predict the properties of gravity from atomic and nuclear physics? the properties of a traffic jam from those of individual cars? the significance of the sign, "Joe's Bar and Grill", from a knowledge of gas-discharges? the properties of 1014 synapses in the human brain from the properties of the approximately 103 properties of physics, the 10 questions treated by chemistry, or the 10 bits of information in the DNA chain in biology? (2) Experimental and logical predictability. There is one kind of practical indeterminacy that derives simply from the fantastic complexity of the human brain. There is a second kind of indeterminacy: the logical invalidity of self-prediction, i.e., scientific predictability in the realm of interpersonal human actions affects the nature of the action, as discussed by D. M. MacKay. (3) The role of subjectivity. The world is divided into two parts; yet these two parts are inseparable. There is the world of physics, the external half-world in which spoons are picked up and dropped again. There is also the world of cybernetics, the internal half-world in which the choice is made to pick up a spoon and to drop it. "The result is that the world of physics and chemistry is only half a world. It's the world 'out there.' It is the world without values, without love, without death, without vomiting."
Commoner argued that the work of Koniherg, Lederberg and Crick establishes clearly on empirical grounds that life transcends chemistry. He restricted himself to a particular aspect of biology, namely the property of life that involves inheritance, self-duplication, replication. In the "central dogma", as set forth by Crick, it is proposed that DNA determines RNA, RNA determines protein, protein determines inheritance, and the reverse processes are forbidden. Commoner interprets recent experiments that show that when DNA is synthesized by a protein (DNA polymerase), the biochemical specificity of the polymerase influences the nucleotide sequence of the DNA, as contradicting the "central dogma" because it shows that the source of genetic specificity (protein) is derived partially from DNA, and that the specificity of DNA is partially derived from protein. Thus he argues that "it is now clear that the origin of genetic specificity in self-duplication is not monomolecular.
It does not come from DNA; it comes from the interaction of an array
He argues further that the work of Nierenberg has shown that the code
the DNA nucleotide sequence into the amino acid sequence in proteins
is not universal
(empirically, seven out of twenty cases were not universal). Finally he argues
that not even chemistry has been reduced to physics since it is not possible to
use quantum mechanics to predict otherwise unknown molecular structures.
A final quote from Commoner may be appropriate to conclude this summary:
I think the trouble with molecular biology is that it's a brilliant attempt to reduce biology to old-fashioned and outmoded physics. Atomism works beautifully in a cer tain realm of physics-in atomic physics It may
well turn out that atomic physics is a special case in which atomism works and that in the rest of the universe we are confronted with a totally new problem.