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

The Triple Helix: Gene, Organism and Environment. By Richard Lewontin. Cambridge: Harvard Univ. Press, 2000. Pp. 136, $22.95.

If niches do not preexist organisms but come into existence as a consequence of the nature of the organisms themselves, then we will not have the faintest idea of what Martian niches will be until we have seen some Martian organisms in action. (p. 51)

In The Triple Helix, Richard Lewontin reviews and critiques the current state of biological science. The quote above sums up the argument of the book: life is not only more than the sum of its parts, it is a complex set of relationships to which inadequate credence is given. The Mars lander story serves as a stark example of some limits of modern life science at many levels.

The Triple Helix is of the same genre as--and vaguely reminiscent of--P. B. Medawar's Advice to a Young Scientist. Both are works of respected senior scientists looking at their own fields with experienced, objective, and occasionally cynical eyes. They are anecdotal works rather than frequently footnoted scientific publications. This sort of book lets the rest of us experience some of what the author's students and fellows are exposed to routinely.

The first three chapters comprise a set of lectures given by Professor Lewontin and previously published in Italy. As such, the book is aimed at an audience with at least an undergraduate-level understanding of genetics, developmental biology, and ecology. The fourth chapter, which serves as a summary, was added for this publication. The book can be read as four separate essays or, at only 126 pages, as an entire unit. Well-placed figures help clarify some complex examples. The model organisms are plants and nonhuman animals, and some assumption is made that the reader is familiar with organisms by genus and species. Unfortunately, there are few direct references, and it is occasionally difficult to know whether the author's assertions are supported by dependable evidence.

Chapter 1, "Genes and Organisms," begins by briefly presenting the historic context of embryology and organismal development up to the current emphasis on molecular genetics. Lewontin uses clear examples to demonstrate that the phenotype of an organism is dictated by more than just the biochemical constitution of the DNA. The thrust of the chapter is to remind those enamored of the genetic code that a string of nucleic acid is not omnipotent; necessary but not sufficient. Between the lines are glimpses of a molecular genetics culture concerned with the veins of the leaves of the trees of the forest. The author is not criticizing the science, or the value of molecular genetic studies. Rather, he is concerned about the loss of perspective. Chapter I is the most strongly written chapter of the book, reflecting, perhaps, the author's familiarity with the subject.

Chapter 2, "Organism and Environment," is a discussion of co-evolution. Very nicely presented is the thought-provoking point that environmental niches exist only when they are filled. Otherwise, feeding strategies or nesting designs are invisible. Conversely, organisms are defined by how they interact with their environment: they swim and eat plankton, or fly and mate for life, or run and hunt in packs. Thus, until an organism details it, an environmental niche does not exist and vice versa: the organism and niche must evolve together as they are interdependent. The Mars surveyor example, quoted above, shows the problem with expecting organisms to exist only within niches as we understand them: if there is not an organism doing what we expect, then we have not defined the niche correctly.

In Chapter 3, "Parts and Wholes, Causes and Effects," Lewontin criticizes the drive to break organisms into understandable bits. Organisms are heterogeneous and their parts are not as discrete as Descartes' machine model would have them be. Reductionist efforts to study living organisms and their environments confront a Heisenberg uncertainty principle, as it is...