Popular Science Monthly/Volume 83/September 1913/A Biological Forecast
| A BIOLOGICAL FORECAST[1] |
By Professor G. H. PARKER
HARVARD UNIVERSITY
THE biologist, like other organisms, has been evolved. The mutations of the Greek and Roman period never established themselves as permanent stocks. They were crushed out by that rank growth of political and theological weeds that finally destroyed itself by its own vegetative excesses. The prototype of the biologist of to-day is essentially a modern product and came into existence with the Renaissance. He is the man who lighted our torch of learning and handed it on to us. But this naturalist of the early days bears almost no resemblance to his modern descendant. Like all reformers, he was an eccentric oblivious alike to popular praise and ridicule. I picture him now with his collecting net under his arm, his hat bristling with the pinned trophies of the hunt, and the pockets of his great coat distended with bottles and phials, which, be it said to his honor, came home fuller in contents than they went out. He widened our horizon by discovering a charm in the reptile and the worm and, with his hand-lens as an instrument of war, he conquered the unknown inhabitants of slimy pools and green puddles. He was indeed in all respects the veritable "bug hunter." I might here quote with perfect appropriateness as descriptive of his sympathy with nature, a certain well-known passage about books in brooks and sermons in stones but I have been instructed to avoid anything that resembled a Phi Beta Kappa oration and so I desist.
Lest you think I have overdrawn my picture of our ancient progenitor, let me read to you a sentence or two from the pen of one who well represented his class and whose book, a "Syonymic Catalogue of the Macrolepidoptera of North America," was a delight to my boyish heart. I quote a few sentences of advice as to costume.
How detailed and considerate the instructions are! That these old naturalists were proud of their outfits, we can judge from the fact that Linnæus, the passed master of them all, had his portrait painted in his Lapland collecting costume. There are many descendants of these worthies at this board to-night, but where among us is a single representative. As Joseph Jefferson once said in describing his own person, we find ourselves disguised in the clothes of gentlemen, and no one here this evening has moistened his lip with "Mountain Dew," not to mention lemon-juice.
But what did these old masters do for us? They undertook and partly performed the enormous task of delivering to us a descriptive catalogue of the animals and plants of the world. To be sure this seemed a simpler proposition in the old days when, as Linnaeus declared, there were as many species as had been created in the beginning. But even then the number must have seemed considerable, for Linnaeus himself gave us descriptions of over four thousand species of animals. Probably, however, he had no suspicion that the total of described animals alone was to rise in our day to half a million and even after this heavy draft, nature would still have the appearance of inexhaustibleness.
But nature is not only vastly richer in species than the older naturalists probably suspected; she is continually at work creating new forms. The simple faith of Linnaeus in the special creation of animals and plants was forever overthrown by Darwin, whose "Origin of Species" established a new point of view for this whole question. And recent evolutionary work has shown that organic transformation is not only in progress to-day, as it has been in the past, but, in the hands of man, it is rapidly assuming the aspect of an important element in civilization. Within the last few years such mastery has been gained over the factors controlling the color of the hair of some of our smaller and more rapidly breeding mammals that, within reasonable limits, a pure breed of guinea pigs of a previously designated color, for instance, can be produced in an incredibly short time. And when it is kept in mind that some of the colors thus produced had long been sought in vain by the old-fashioned animal breeders, the advantage of the new methods over the old must be apparent. Instances of this kind give us good reason for believing that before many years have passed useful forms of animals and plants will be produced on demand, not in the somewhat haphazard way of the present practise of breeders, but with the certainty and precision with which a modern inventor constructs a new piece of machinery.
This change in the aspect of evolutionary matters can not be better illustrated than by three quotations that preface one of the most important publications on evolution in the last decade, "Species and Varieties, their Origin by Mutations." The quotations, which are arranged in historical sequence and come from the three great masters in this field, are as follows:
The origin of species is a natural phenomenon.—Lamarck.
The origin of species is an object of inquiry.—Darwin.
The origin of species is an object of experimental investigation.—De Vries.
The last statement, that the origin of species is open to experimental study, is the keynote to modern evolutionary work. But it is not simply the keynote to this particular part of biology; it marks a change in front of the whole army of biological workers whereby the science of the organism is being transformed from one of observation pure and simple to one which includes experiment. We sometimes hear astronomy, chemistry, physics, etc., described as the exact sciences, and our friends in these domains of knowledge occasionally take a hidden pleasure, I suspect, in intimating that what lies outside their realm, including biology, must belong to the inexact category. That biology has not been exact in the sense that physics and chemistry have been, we freely admit, but physics was not always exact, and before the days of Lavoisier, chemistry had few quantitative results of which it could boast. Biology, from the nature of the materials it has had to master, has of necessity been slow in growing to that stage where it was imperative to use those refined methods that have long been employed by physics and chemistry. But these methods are rapidly being assimilated by the more progressive members of the biological fraternity, who are discovering that there is nothing inherently inexact about the subject-matter of biology or its treatment. This subject-matter is open to the same searching method as is that of the so-called exact sciences. But though we are not yet admitted to full fellowship with these sciences, we are at least the center of the observational group and, if we wished to retaliate on our good friends of the exact sciences, we might declare them non-observational with as much reason as they call us inexact. But you will accuse me of falling into a word controversy. And such it would be. The truth is that biology is rapidly becoming experimental, and in doing so it necessarily assumes all those methods and procedures that have long been the special possessions of the exact sciences. As a result of these coming changes we expect to see biology established in a short time as an observational science of a highly exact order.
This general change, though characteristic of the last decade, may in reality be said to be no change at all, for the experimental attack on biological problems had its inception in the early days of the science. Its growth, however, has been limited almost entirely to the narrow field of human physiology, and the physiological laboratory is now proving to be a source of inspiration and help to the biologist as he faces the new set of problems put before him by the experimental method. It is customary to date the beginning of experimental physiology from Harvey's discovery of the circulation of the blood, not because this important discovery was a central biological fact, but rather for the reason that it was the first considerable discovery in physiology that was made by a rigid application of the experimental method, a method which has made possible almost all the subsequent progress in this field of research.
It is the acquisition of the experimental method that is converting the old biology into the new. Never before in the history of the science has there been such an expansion as the last decade has witnessed. Without diminishing activity in the fields that have long been under cultivation, this change has added enormously to the territory open to biological investigation. We still need revised and improved catalogues of the animals and plants about us, even though we now know that the unit of this kind of work, the species, is a highly artificial conception and that in nature all is in slow but continual flux. We need to know more about the distribution of animals and plants past and present, about their gross structural composition, their methods of development, their mutual interdependencies, their lines of descent, and the like. Biology is still a rich field for the purely observational worker, but the new territory laid open by the experimental method is, to my mind, the land of greatest promise. This method brings us face to face with some of the most fundamental problems of the organism, the solution of which, in my opinion, will yield results of the utmost importance to mankind. At this stage it would be presumptuous to attempt to predict what these results may be. But I can not let the present moment pass without hazarding a guess at a few of them.
No organism can exist long without food. Every animal and plant is appropriating materials by the chemical readjustment of which it is gaining the energy necessary for its own activities. We, as organisms, form no exception to this general rule. Our food, like that of other omnivorous animals, comes from animal and plant sources, but ultimately all food is drawn from the green plant. Destroy completely all green plants and in a short time all other organisms on the earth would die of starvation. The green plant is the one independent organism on the globe; all others are in a way parasitic. As you well know, the green plant in sunlight elaborates starch from water and carbon dioxide, and the primitive food thus synthesized becomes the basis for further changes whereby nitrogen and other materials are built into the body of the plant. Thus arise the starches, sugars, oils and proteid materials which constitute the substance of the plant body and which serve us as foods, absolutely essential to the continuance of our lives.
In my opinion the time is not far distant when we shall be emancipated from this slavery to the green plant. No seriously minded chemist of the present day believes that there is any inherent impossibility in the repetition of the chemical processes of the organism, in the laboratory. The days of this form of vitalism have long since passed away. The difficulty that confronts the biological chemist in attempting to repeat the chemical processes of the organism is the enormous complexity of even the simpler of these operations. Hence he has not yet achieved that kind of success that even the scientific public seems to expect of him. But is this expectation reasonable? Are we warranted in finding him wanting because he has not yet made an amœba? I think not. To ask him to make an amoeba is like asking an engineer to duplicate New York City. With infinite toil and pains it could be done. But who or what would be the better? One New York is enough. Better study the processes of New York or the amœba than attempt to duplicate in totality either organism and, having learned what these processes are, apply them to human welfare. This is the attitude we must assume toward the green plant. We must learn its processes and, having learned them, we must apply them to our needs.
If the green plant in sunlight can elaborate from water and carbon dioxide one of our chief food substances, starch, there is no reason why the biological chemist should not discover the secret of this process and imitate it on a commercial scale. Starch, I believe, has never been synthesized, but some sugars have been so constructed. Two years ago Stoklasa and Sdobnicky made the remarkable discovery that by the action of ultraviolet light on nascent hydrogen and carbon dioxide sugar was formed. Such discoveries as this suggest the means by which we are to throw off our slavery to the green plant and I am convinced that in time this overthrow will become so complete that our staple foods will be the products of the biological chemist.
From this standpoint the attitude of many of our pure food enthusiasts seems to me entirely erroneous. Why object to the cheaper synthetic colors and flavors in prepared foods provided they are not poisonous in themselves and contain no injurious by-products? As a matter of fact these very colors and flavors are often purer than the natural materials. From the point of view of public morals, such mixtures should be rightly labeled, but to stigmatize them as necessarily inferior to the natural products is, to say the least, unprogressive. We do not object to artificial indigo because the chemist has superseded the green plant in its manufacture. Why, then, should we object to a currant jelly composed of wholesome artificial products? It may not only be as good as the old-fashioned kind, but I can imagine that a connoisseur in this new venture might impart to it a flavor even more delicate than that from the kitchen. Our descendants, I am sure, will some day sit down to dinners of synthetic dishes, the products of clean laboratories, with as much appetite and pleasure as we now partake of a meal hewn from the animal and dug from the earth, and we must not object if they prefer, on esthetic grounds, the source of their food to that of ours.
But food is only one of the many things we need. We number ourselves among the very few organisms that use tools and we need energy to drive many of our tools. Historically we have abandoned in much of our work the muscle for the steam engine. Contrast the construction of a modern building by a handful of Italian workmen and a donkey engine with the wall pictures we have of the long lines of Egyptian slaves straining every muscle as they pull a heavy load at the end of a rope.
But have we done best to ignore the muscle? When this organ is functioning at its highest, it yields two kinds of energy, heat and power to do mechanical work about in the proportion of two thirds heat to one third work. From the energy that enters the ordinary steam engine about one tenth is given back in work and the other nine tenths are dissipated as heat. Even in the highest grade of turbine engines, this efficiency seldom reaches as much as a quarter of the available energy. Thus the muscle returns us over thirty per cent, of its energy in effective work, and the best steam engines only about twenty-five per cent. If we knew the secret of muscle action, I have no doubt that a mechanism could be constructed that would far outrun the steam engine as a means of doing work.
Another kind of energy that we seek is light. Primitive man was forced to content himself with the sun by day and the moon and stars by night. When he first struck fire, artificial light came as well as warmth, and from that day to this we have witnessed a long succession of improvements in the production of artificial light. But in none of these has man rid himself of the association of heat with light. Every device for illumination that has been put forward yields more heat than light. Our ordinary gas flame yields between one and two per cent, of light and the remaining ninety-eight or -nine per cent, is lost in heat. No wonder that the modern gas corporation is advertising itself as a convenient source of heat and power. Many of us who serve it as consumers have come to regard this by-product as the most important part of its output. We can at least feel what we are paying for, if we can not see it. But the electric lights far outrun the gas lights in efficiency. An ordinary carbon incandescent lamp yields about six per cent, of light to ninety-four per cent, of heat, the arc lamp about ten per cent, of light, while the mercury arc has climbed to the enormous efficiency of almost half light to half heat. This indeed is prodigious compared with the means of illumination of a few years ago.
But what have the organisms to teach us in this respect? Many animals and plants are luminous. The simple one-celled animals, jelly fishes, worms, clams, insects and common fishes all have luminous representatives. But who ever heard of the sea being appreciably warmed by its phosphorescence or of a child who burned his finger with a firefly? Animal light is produced without heat, it is immensely the most economical form of light. Repeated and recent study of the firefly light has shown that all of its energy lies within the visible spectrum, that it contains not a measurable vestige of heat. Its efficiency is complete and could we discover, as we shall some day, the secret of the firefly light, the only occupation that would be left for our municipal illuminating plants would be that of heat generators.
By this time you must surely have caught the drift of my idea. For ages past animals and plants have been slowly evolving processes on some of which we have come to be absolutely dependent. Biology has now advanced to that stage where the study of these processes is beginning to be seriously undertaken. In my opinion the operations of plants and animals will serve as models on which to build up industry on a scale that human endeavor has never dreamed of before. Our modern industrial world supplies man's wants by means of what I may call inorganic devices. The future industrial world will draw more and more from organic models. In my opinion we are on the verge of an enormous expansion in applied biology. A century from to-day and our work will look as small and insignificant in comparison with the biology of that period as Franklin's electrical experiments do when brought face to face with the enormous electrical expansion of modern times. He saw in nature a few manifestations of a gigantic power which the modern man of science has brought under control. It is vouchsafed us in this early day to see dimly and indistinctly the powerful forces of organic nature and to receive the conviction that in the not distant future, these too are to be bridled and led by man. Such to my mind is the forecast of biology.
- ↑ An address delivered at the annual banquet of the Brown University chapter of Sigma Xi, May 28, 1913.