"The properties of species map the shape of the underlying external world, just as when we sprinkle iron filings on a sheet of paper lying on a magnet, the filings form a pattern that maps the underlying magnetic field. In a curious sense the study of the organisms is really a study of the shape of the environmental space, the organisms themselves being nothing but the passive medium through which we see the shape of the external world. They are the iron filings of the environmental field." (p. 44)Although the first three (of only four) chapters of The Triple Helix were originally lectures given in Milan, you will not figure that out from reading the chapters themselves. They sound like they were written specifically to be a book. They are well integrated and don't feature the normal language one expects from lectures that are turned into books. This is a very good thing for those of us who like to read books as books and not as a collection of disjointed essays or oral ramblings converted to print.
Lewontin highlights and emphasizes the combined factors of phenotype development. He criticizes the view that only genotype specifies phenotype. Environment also plays a key role in the equation. Not to be forgotten is "developmental noise", essentially random events within cells, which also comes into play.
Section II, entitled "Organism and Environment" was my favorite of the four. It is often as poetic as it is insightful. Lewontin causes the reader to look at nature and the living world through different lenses. He aptly points out how Darwin was the first to clearly demarcate between internal processes and external ones.
Many metaphors have been invoked for this relation between independent environment and organism. The organism proposes and the environment disposes. The organism makes conjectures and the environment refutes them. (p. 43)Lewontin doesn't stop there, however. He shows how the environment isn't quite as sterile as that. The environment can certainly be shaped by the organisms. In essence, they co-evolve. Not only do organisms change and modify the environment, they build it for their descendants. Were it not for the organisms that gave off oxygen billions of years ago on this planet, species like ours could certainly have not come into being.
The end of Section III features a thought-provoking discussion of the difference between causes and agencies. Basically, we frequently mistake agents for causes. Until we realize this, real problem solving becomes impossible.
Lewontin's final section points the way for the future. He isn't a fanatic when it comes to some of the "radically different ways of studying organisms or for new laws of nature that will be manifest in living beings" such as chaos theory. Non-biologists frequently try and apply their area of study (mathematics, physics, religion, etc.) to the biological world without first understanding the field of biology on its own terms and with its own unique characteristics.
It is not new principles that we need but a willingness to accept the consequences of the fact that biological systems occupy a different region of the space of physical relations than do simpler physico-chemical systems, a region in which the objects are characterized, first, by a very great internal physical and chemical heterogeneity and, second, by a dynamic exchange between processes internal to the objects and the world outside of them. That is, organisms are internally heterogeneous open systems. (p. 113)It's an exciting and challenging field of study which even with all the discoveries of the 20th century still has many more to come in the future.
"Taken together, the relations of genes, organisms, and environment are reciprocal relations in which all three elements are both causes and effects. Genes and environment are both causes of organisms, which are, in turn, causes of environments, so that genes become causes of environments as mediated by the organisms." (p. 100-1)from the publisher:
The central message of this book is that we will never fully understand living things if we continue to think of genes, organisms, and environments as separate entities, each with its distinct role to play in the history and operation of organic processes. Here Lewontin shows that an organism is a unique consequence of both genes and environment, of both internal and external features. Rejecting the notion that genes determine the organism, which then adapts to the environment, he explains that organisms, influenced in their development by their circumstances, in turn create, modify, and choose the environment in which they live.
The Triple Helix is vintage Lewontin: brilliant, eloquent, passionate, and deeply critical. But it is neither a manifesto for a radical new methodology nor a brief for a new theory. It is instead a primer on the complexity of biological processes, a reminder to all of us that living things are never as simple as they may seem.
Richard Lewontin is Alexander Agassiz Research Professor at the Museum of Comparative Zoology, Harvard University. His many books include Biology as Ideology, It Ain't Necessarily So: The Dream of the Human Genome Project and Other Illusions, and Human Diversity.