Genetic Determinism as a Failing Paradigm in Biology and Medicine: Implications for Health and Wellness

Article excerpt

Editor's Note. This piece is excerpted, with permission of the author and the publishers, from a chapter in M. S. Jamner and D. Stokols's (editors) Promoting Human Wellness: Frontiers for Research, Practice and Policy (2000, University of California Press). An epilogue specially prepared by the author follows. The chapter critiques genetic determinism. Such causality is often claimed in a simplistic manner. It seems important for social work educators to be informed about the complexity of interactions between genes and their environments, so they can alert students to controversies in the field. Other books in this area include Living With the Fluid Genome by Mae-Wan Ho (2003, Institute on Science in Society,; Brave New Brain: Conquering Mental Illness in the Era of the Genome by Nancy Andreasen (2001, Oxford University Press); Inside and Outside: Gene, Environment and Organism by R. C. Lewontin (1994, Clark University Press); and It Ain't Necessarily So: The Dream of the Human Genome and Other Illusions by R. C. Lewontin (2000, Granta).

Richard C. Strohman, PhD, is professor emeritus, Department of Molecular and Cell Biology, University of California, Berkeley. He has had a research career in cell and tissue growth regulation and cellular differentiation using molecular and cell approaches. He has been chair of the University of California, Berkeley, Zoology Department (1973-1976) and director of Berkeley's Health and Medical Sciences Program (1976-1979).

Retired in 1991, Dr. Strohman continues to teach courses dealing with the interface between biology and medicine and the growing crisis in theoretical biology. His view is that genetic determinism, the major component of biological reductionism, is increasingly unable to contend with newer findings of biological complexity and that a new and more holistic scientific theory of living systems is required.

Crisis: Where Is the Program?

The trouble with the extended theory of the gene is that genetic elements, while critical, are only one aspect of biological regulation. They cannot, in themselves, specify details of organismal phenotype, including complex diseases like sporadic cancer and cardiovascular diseases. To be sure, there are cases in which genes may be said to "cause" attributes of an organism, but these are rare; in the realm of human diseases they account for about 2% of our total disease load. (1) For the most part, complex attributes ... phenotypes of organisms ... are not caused by genes even though genes are the ultimate agents used to create phenotypes. But if genes don't determine us, if our disease causality cannot be located in genetic agents alone, if developmental processes characterized by high fidelity adherence to species form cannot be reduced to genetic programs, if the source of evolutionary change is not traced solely to random genetic mutation, then what does determine us? Where is disease causality located, where and what is the nature of programmed growth and development in living organisms, and what is the creative source of new morphology and function acting as substrates for natural selection? In short, if the program for life is not in the genes ... and organisms are clearly programmed ..., then where is the program?

The short answer is that the program is in no one place; it is distributed at many levels of the organism, and all levels are open to environmental signals. Controls may be found distributed in gene circuits, in metabolic networks, in cytoskeletal structures, in membrane units, in extracellular matrix elements, and finally in the cell as a whole and in networks of cells at the various levels of organization above the cell. These levels of control each have their own rules, and all levels are interactive with one another and, in the case of cells and organisms, with the world around them. The major new idea here is that these levels of control are not reducibly connected; it is not possible, for example, to reduce common cancer to rules that govern DNA, (2) just as it is not possible to reduce intelligence simply to the laws governing ion fluxes in brain neurons. …