Intellectual Traditions in the Life Sciences: Molecular Biology and Biochemistry

INTELLECTUAL TRADITIONS IN THE UFE SCIENCES: MOLECULAR BIOLOGY AND BIOCHEMISTRY SCOTTF. GILBERT* I Biological science is a vibrant, collective human endeavor consisting largely of controlled experiments and their critical interpretations. This does not, however, constitute an exhaustive catalog of the component parts of the life sciences. Another element is the context in which these experiments are integrated [I]. I am not speaking here of Kuhnian paradigms or of heuristic constructs, but of intellectual traditions which are not proved or disproved by experiment and which, of themselves, rarely suggest new investigations.1 Nevertheless, these intellectual traditions subtly guide the direction of the entire enterprise of biology. Most analyses of the intellectual traditions in biology have focused on the integration of biological sciences into the larger intellectual ferments of the eighteenth and nineteenth centuries. This essay, however, will attempt to look at the intellectual currents which led to the separation of molecular biology and biochemistry during die mid-twentieth century. Both ofdiese disciplines attempt to understand die physical basis oflife; yet molecular biology was founded by scientists who not only were untrained in biochemistry but were antagonistic to it. In particular, one of the most influential founders of molecular biology, Max Delbr ück, "deprecated biochemistry," claiming that the analysis of the cell by biochemists had "stalled around in a semidescriptive manner without noticeably progressing towards a radical physical explanation" [2, p. 22]. This bias was transmitted to several of his students and colleagues. Replying in unkind, the famed nucleic acid biochemist Erwin Chargaffhas This paper was submitted in the first Dwight J. Ingle Memorial Young Writers' competition for authors under 35. ?Department of Biology, Swarthmore College, Swarthmore, Pennsylvania 19081. 1Foucault has suggested die term "episteme" forsuch a concept; butas he claims thatonly one episteme defines die condition of scientific knowledge at any time, I find diat "intellectual tradition" denotes what I mean more readily.© 1982 by The University of Chicago. All rights reserved. 0031-5982/83/2601-0316$01.00 Perspectives in Biology and Mediane, 26, 1 · Autumn 1982 151 accused the molecular biologists of "practicing biochemistry without a license" [3, p. 140] and believes that molecular biology has severely impeded the flow of scientific creativity. This animosity between biochemists and molecular biologists was especially vigorous in the 1940s and 1950s. This essay will attempt to show diat biochemistry and molecular biology are die current incarnations of two complementary traditions in biological science, and that they embody radically different ideas concerning the nature of life. II "The ultimate goal of biochemistry" according to Fruton and Simmonds , "is to describe the phenomena that distinguish the 'living* from the 'nonliving* in the language of chemistry and physics" [4, p. I]. But neither they nor anyone else has been able to create a set of criteria for the definition of life. To Claude Bernard, the founder of the cell physiology, which eventually gave rise to the disciplines we will be discussing, "... there is no need to define life in physiology." Such attempts, he claimed, were "stamped with sterility." Bernard concluded, "It is enough to agree on the word life to employ it; but above all it is necessary for us to know that it is illusory and chimerical and contrary to the very spirit of science to seek an absolute definition ofit. We ought to concern ourselves only with establishing its characteristics and arranging them in dieir natural order of rank" [5, p. 19]. In the absence of any consensual accord, biology has evolved two traditional approaches to characterize the physical basis of life. In each, the "natural order of rank" is the reverse of the other. The first tradition emphasizes the phenomena of growth and replication as die major vital characteristics. Organisms are seen to increase in size and numbers and are thus akin to crystals. The second perspective focuses on metabolism as life's prime requisite, whereby an organism retains its form and individuality despite die constant changing of its component parts. In this respect, living beings resemble waves or whirlpools. These alternative crystalline and fluid models of organisms have interacted with each other for the past hundred years. It will be shown that "classical" biochemistry largely retained the metabolic model oflife whereas...