The Triple Helix: Gene, Organism, and Environment (review)

Richard Lewontin, a student of the pioneering population geneticist Theodosius Dobzhansky, is currently the Alexander Agassiz Research Professor at the Museum of Comparative Zoology at Harvard University. Lewontin takes advantage of his considerable linguistic skills and academic credentials to advance the view that there is a symbiotic relationship between the gene, the organism, and the environment. Lewontin represents this symbiotic relationship metaphorically as The Triple Helix.

Biology is substantially influenced by Rene Descartes' metaphor of man as machine and Charles Darwin's theory of evolution by natural selection. Both Descartes and Darwin were original thinkers in their time. Lewontin argues, however, that in today's era of modern biology, Descartes' metaphor and Darwin's theory cripples modern biological thinking. Descartes' metaphor and Darwin's theory, according to Lewontin, result in a simplistic understanding of the developing organism and are inconsistent with available evidence that the "ontogeny [development] of an organism is the consequence of a unique interaction between the genes it carries, the . . . external environments through which it passes during its life, and random events of molecular interactions within individual cells" (18; emphasis added).

The Triple Helix was originally presented as a series of lectures at the Lezioni Italiani in Milan sponsored by the Sigma-Tau Foundation. The lectures were subsequently compiled as The Triple Helix and published in Italian in 1998. The English version was published in 2000. The structure of the book leads logically from genes to organism to environment to a discussion of parts and wholes, and causes and effects. Lewontin added a fourth chapter, not part of the original Italian lecture series, on the "Directions in the Study of Biology."

In chapter one, "Genes and Organism," Lewontin discusses the relationship between the gene and the organism. Contrary to Descartes' metaphor of man as machine, Lewontin introduces evidence demonstrating that the development of an organism is the result of a symbiotic relationship between genes, external environments, and random interactions. The organisms used for demonstration purposes, however, are plants and lower organisms such as the drosophila fruit fly. One is left to extrapolate the results to higher organisms such as primates.

Most readers will be familiar with terms such as gene, organism, and environment as they appear in the text, even if only in a popular sense. In chapter one Lewontin introduces the reader to a less familiar term, the oft neglected idea of "developmental noise." Developmental noise, a fundamental feature of contemporary genetics, occurs when random events take place within cells. For example, it is this randomness, in the form of developmental noise, Lewontin contends, that results in identical twins having different fingerprints. If fingerprints were solely determined by genetic code, one would expect identical twins, who share the same genetic code, to have the same finger- prints.

Modern biology, in addition to adopting Descartes's metaphor of man as machine, has adopted Darwin's theory of evolution by natural selection. Part of Darwin's theory suggests that in the process of adaptation, the organism and the environment are independent of each other. In chapter two Lewontin asserts that the autonomy of the organism and the environment is "clearly wrong." According to Lewontin, organisms are continually changing and "constructing" their external environment by their life activities rather that adapting to it in the Darwinian sense.

In chapter three, "Parts and Wholes, Causes and Effects," Lewontin claims Descartes' mechanical model of the world is corrupting our understanding of how parts relate to wholes and how causes relate to effects. "Success of the [machine] model . . . has led to an overly simplified view of the relations of parts to wholes and of causes to effects" (72). This becomes clear, for instance, when dissecting an organism. What are the appropriate parts or units of study of the organism, Lewontin queries. Molecular biologists insist the molecule is the only legitimate unit of study. The organismic biologists, on the other hand, "atomize" an...