Thoughts About Biology

Abstract

Everything expands and changes and so does our knowledge of biology. Everybody says that this is so. Even though I have been a biologist only 30 years, still I have myself seen sufficient change in our science to be assured that such change is in fact taking place. In the first place we have learned a lot of plain old facts: How respiration works, a lot about how photosynthesis works (but not all), a lot about how all the different amino acids get made, a lot about what hormones there are, a little about how hormones work, a lot about the description of how development takes place, a great deal about genetic material. We have seen enough to convince me that there is one great class of biological problems which, if followed to its ultimate lair, turns out to be biochemistry. They are problems which ultimately revolve around the path of carbon, the isolation of enzymes, etc., etc. I think this is true of much of genetics, all of physiology, much of em-bryology, much of ecology, and, in a sense, of morphology and anatomy. These disciplines all deal with things that turn upon molecules and chemistry in a rather direct way. We know, for example, that to discover how a gene does what it does, all we have to do is find out what enzyme it causes to be made and then find out what that enzyme does. It is perfectly clear, then, that if one wishes to tackle any of the biological problems of this class, he has to be a biochemist, and so the wise student will become a biochemist. It appears to me that beyond this stratum of molecular biology, or above it, as some of my friends would say, is a second stratum; a stratum which contains problems of strategy, of programming, of how to use the various and ingenious molecular devices invented by creatures to make a creature or a society. To this class of problems I give the name "systems biology." The first and obvious example is the neural network made of cells, made of molecules, to be sure, but capable of, in some mystic way, processing, storing, retrieving, and acting on sensory information. The problem of how the neural network works has elements which are not intuitively obvious even if one were to know a great deal about neurobiochemistry. We want to know the logic which the neural network uses, the program which it uses for problem solving, and so on. This is a biological problem which is upon a level of abstraction higher than that of our neoclassical molecular biology. Or to cite another example, the successive acts by which sister cells differentiate to form a creature. This again appears to be a problem in programming-programming of the use of the information contained in the genetic material. Or the flux of material through a community of plants and animals, the strategy of who eats whom and why. Or the problem of why the photosynthetic unit has 2400 chlorophyll molecules instead of some other number. These are problems which biologists by and large are not able to tackle profitably. In the first place they have in common the quality that their study requires not only knowledge of biology and of biochemistry but also knowledge of logic, information theory, network theory, and analytical mathematical ability. ·And it appears clear to me that the great forward steps in these complicated problems of biological systems analysis are being made not by formal biologists but by mathematicians, physicists, and even engineers whose interests have turned (probably for some sinister subconscious reason) to biology. And it should in turn be clear to any promising young person who wishes to solve complex problems of biology that he should start out by becoming, say, a physicist or a mathematician. It appears to me that the frontiers of our knowledge in biology are advancing more rapidly than is the breadth of wisdom and interest of biology departments. More than ever before, it seems to me, we teach people the wisdom they need to solve yes-terday's problems instead of tomorrow's. The biologist of today already needs much more wisdom in quantum chemistry and symbolic logic and systems analysis and basic physics than he ordinarily has at his disposal. But we do little to insure that the next generation of biologists will possess such skills and wisdom. Biology is becoming a rigorous science with sophisticated laws and operational rules and theorems and even a central dogma; it has everything but sophisticated instruction about how to become a biologist.