The Search for 'Fitness' in Nature

Biophysicist Harold Morowitz spent his last sabbatical pondering the cosmic mysteries aboard a yacht anchored off the West Maui mountains in Hawaii. The result of his musings can be found in Cosmic Joy and Local Pain: Musings of a Mystic Scientist (Charles Scribner’s Sons, 1987). [For a review of the book, see THE SCIENTIST, September 21, 1987, p. 20]. The first possession he packed for his trip was Lawrence Henderson’s book The Fitness of the Environment. In this excerpt, Morowitz

Oct 19, 1987
Harold Morowitz

Biophysicist Harold Morowitz spent his last sabbatical pondering the cosmic mysteries aboard a yacht anchored off the West Maui mountains in Hawaii. The result of his musings can be found in Cosmic Joy and Local Pain: Musings of a Mystic Scientist (Charles Scribner’s Sons, 1987). [For a review of the book, see THE SCIENTIST, September 21, 1987, p. 20]. The first possession he packed for his trip was Lawrence Henderson’s book The Fitness of the Environment. In this excerpt, Morowitz describes Henderson’s scientific approach to the questions of fitness and design in nature.

Looking for spiritual meaning within science is not a new idea. It was quite a popular intellectual activity in the 18th and 19th centuries, the period from Newton to Darwin. One of the best examples was the Bridgewater Treatises of the 1830s. These works on natural theology were written by eminent scientists with the purpose of showing evidence of the creator from a study of his creation.

This genre of literature had, at its core, a concept called the argument from design, which implies that we need only examine the world around us to see that it must be the result of a creative intelligence rather than blind chance. However, the early adherents of this viewpoint always carried their argument at least one step further than its original logic and formed a chain of reasons that went as follows: The observed world—implies: a creative intelligence—implies: a creator—implies: the Judeo-Christian God—implies: the established Church.

Those scientists who rejected the second and third or fourth implications in the sequence threw out the entire chain of reasoning, thus abandoning the first step, the argument from design, without giving it the consideration it deserves.

Following the work of Darwin as well as that of the 19th-century geologists, arguments found in the Bridgewater Treatises were dismissed as theological sophistry by many within the scientific community. The argument for the “creator” based on the designs of the “created” was totally rejected on the grounds that Darwinian fitness would result in the same remarkable adaptation of organisms to the laws of nature and boundary conditions of the planet. Scientists were locked in a bitter confrontation with established religions and instinctively turned their backs on all arguments suggestive of order or purpose. Yet the “will to survive,” or the “thrust for fitness,” that was introduced had a teleological content that evolutionary biologists such as Thomas Huxley and Ernst Haeckel chose to ignore. They replaced a religious metaphysics with a scientific metaphysics, but were unaware of the substitution.

In 1913, however, fitness and design were re-examined from a new scientific perspective. Distinguished Harvard professor of philosophy Lawrence J. Henderson wrote his profound and controversial book. Some 64 years had passed since Charles Darwin’s Origin of Species had introduced the idea of “fitness” as the criterion of success in the struggle for survival.

Simultaneously with the rise and triumph of Darwinian evolution, physiology developed as a sophisticated science, using the understanding of physics and chemistry to explain the mechanisms of biological activity at every level. Henderson is. a leader in that tradition. Indeed, some of his work on biophysical chemistry is still referred to today. He took a fresh view of fitness in terms of the new knowledge of physical chemistry and the ascendance of the atomic theory. He examined the argument from design, not from a theological perspective but from deep within science, using the constructs of matter, energy, space and time. He wrote:
But although Darwin’s fitness involves that which fits and that which is fitted, or more correctly a reciprocal relationship, it has been the habit of biologists since Darwin to consider only the adaptations of the living organism to the environment. For them in fact, the environment, in its past, present, and future, has not been an independent variable, and it has not entered into any of the modern speculations to consider if by chance the material universe also may be subjected to laws which are in the largest sense important in organic evolution. Yet fitness there must be in environment as well as organism.

Henderson, arguing in scientific terms, urges us not only to examine the plasticity of organisms in adapting to the environment but also to examine those features of the environment that make life possible. To appreciate these insights, note that he wrote his book before the publication of Niels Bohr’s quantum theory of the atom and four years before the modern theory of valence, telling how atoms are held together in molecules. Biochemistry was in its formative years, awaiting developments in organic chemistry. Most geologists believed that the continents and oceans were quite unchanging features of the earth’s surface. Ecology was but a word and had not reached the status of a science. In this setting, Henderson set forth his views of fitness.

The extent to which this physiologist’s starting point was scientific rather than philosophical can be seen in his words: But we can scarcely think that our present ideas are inadequate for our present purpose, or that, for life, matter will be other than the elements of the periodic classification, energy that set of quantities to which we apply the laws of thermodynamics, and Euclid.

Using physical criteria, Henderson stresses the biologist’s view of the organism, a durable, complex form maintained by the flow-through of matter and energy. He is able to formulate the problem: To what extent do the characteristics of matter and energy and the cosmic processes favor the existence of mechanisms that must be complex, highly regulated and provided with suitable matter and energy as food? If it shall appear that the fitness of the environment to fulfill these demands of life is great, we may then ask whether it is so great that we cannot reasonably assume it to be accidental, and finally we may inquire what manner of law is capable of explaining such fitness of the very nature of things.

The question is whether life with all its subtleties is some accidental property called into existence by events of blind chance or whether it is a more fundamental property of the world of nature. As we study the complex and interrelated aspects of planetary life, are we simply to attribute it all to random events, or are we to seek deep meanings about ourselves and the cosmos? Looking at the evidence, Henderson opted for the latter approach. So do I, but that commitment to meaning only becomes apparent after one spends some considerable effort looking into our understanding of the physics and chemistry of life and the biological applications.

The features looked at in The Fitness of the Environment are the solar system, the exceptional nature of water, the properties of carbon dioxide, the makeup and flow patterns of the oceans, and the chemistry of carbon, hydrogen, and oxygen compounds. After a detailed analysis of these subjects in the light of the science of his day, Henderson focused on the question of whether the Earth is uniquely suited to life or whether other environments might prove equally habitable. He gave special attention to the occurrence of great quantities of water and carbon dioxide on the outside of the solid crust of an astronomical body. After a rather long and detailed discussion of the special properties of the Earth, it was then concluded that “the above catalogued natural characteristics of the environment promote and favor complexity, regulation, and metabolism, the three fundamental characteristics of life.”

Henderson assured himself that his treatment had been exhaustive, no important physical features had been neglected, and no other chemicals would suffice, no other combination of elements from the periodic table would work so well. He finally concluded that life is somehow a property of the evolving universe and “that genetic and evolutionary properties, both cosmic and biological when considered in certain aspects, constitute a single orderly development that yields results not merely contingent, but resembling those which in human action we recognize as purposeful.”

Henderson’s line of reasoning started with the then-current theories and observations of science. He fully accepted the approach of his time and then asked: “Can we by analyzing these results formulate a metatheory that gives us a more extended vision?” After answering this question with a yes, he began to tentatively grope for that metatheory that would tell us more about ourselves and our place in the universe. Knowledge of the material world need not alienate us from more spiritual thoughts; it can indeed guide us to such thoughts.

it is now more than 70 years since the great physiologist set forth his views. Our knowledge of biology and biochemistry is vastly more detailed and extends down to the atomic and electronic level of organization. Our understanding of the planet and the universe is radically different from anything envisioned in the early part of the century. With all these scientific advances, our sense of the reciprocal relationship, or mutual fitness, seems to grow deeper and more profound. The puzzle now has many more parts, but the way in which they fit together remains just as striking.

I share Henderson’s feeling that the remarkable reciprocity between organism and environment cannot be ignored either by scientists or philosophers. The Fitness of the Environment is not widely known among contemporary scientists, many of whom have renounced purpose from a methodological point of view. Yet this rejection has likely been premature.

Morowitz is professor of molecular biophysics and biochemistry, Yale University,

New Haven CT 06520. Copyright © by Harold Morowitz. Reprinted by permission of the publisher, Charles Scribner's Sons