Reports of the National Center for Science Education

Review: Who Wrote the Book of Life?

Who Wrote the Book of Life?: A History of the Genetic Code
Lily E Kay
Stanford (CA): Stanford University Press, 2000. 472 pages.
Reviewed by
Jeffrey M Otto
According to the book jacket, this book consists of "a detailed history of one of the most important and dramatic episodes in modern science, recounted from the novel vantage point of the dawn of the information age and its impact on representations of nature heredity and society. Drawing on archives, published sources and interviews, the author situates work on the genetic code (1953-70) within the history of life science, the rise of communication technosciences (cybernetics, information theory and computers), the intersection of molecular biology with cryptanalysis and linguistics, and the social history of postwar Europe and the United States." This is an accurate, but incomplete, description of the book. In addition, and perhaps more importantly, the book is a discourse on why the author believes that the genetic code is not really a code in the true sense of the word, and why DNA contains chemical and biological specificity but not information per se. In the first chapter, she writes:
My thesis is that molecular biologists used "information" as a metaphor for biological specificity. However, "information" is a metaphor of a metaphor and thus a signifier without a referent, a catachresis. As such, it became a rich repository for the scientific imaginaries of the genetic code as an information system and a Book of Life. The information discourse and the scriptural representations of life were inextricably linked. Metaphors, as I will examine, are ubiquitous in science, but not all metaphors are created equal. Some, like the information and code metaphors, are exceptionally potent due to the richness of their symbolisms, their synchronic and diachronic linkages and their scientific and cultural valences (p 2).
After reading the book jacket, the preface and the first chapter, one is left with the question "Who is the target audience for this book?" As best I can tell, it is aimed at professional science historians. The writing is too difficult and unfriendly to be aimed at the amateur science history enthusiast. Furthermore, the author assumes that the reader already is familiar with the history and the individuals involved. A simple, limited biography on each of the key individuals at the end of the text would have gone a long way to help the reader. It is likely that a neophyte enthusiast who managed to maintain interest while wading through the difficult text would quickly be confused and frustrated by the constant infusion of new names, all without adequate introduction.

Yet I cannot imagine that the professional science historians would be much interested in this book either. The author's approach seems to be more fragmented than unified in her attempt to link molecular biology, linguistics, information theory, and yes, her own personal philosophy into this historical account of the unraveling of the genetic code. Had Kay restricted herself to describing the history of the unraveling of the genetic code, the text would have been much more accessible. This is all the more disappointing because the source material is rich and varied, consisting of quotes, letters, interviews, photographs, and drawings. It is unfortunate that Kay places such a large burden on her reader, expecting that the reader can pull together the salient details and form a coherent picture of this compelling and world-changing story with little help from the author.

While the writing style and her decision to focus on so many disciplines make the book a difficult read, it is actually her apparent philosophy on the nature of information and its relationship with DNA that I have the most problem with. Interwoven with Kay's description of the insights, experimentations, and technology that resulted in the discovery of the genetic code is her description of the researchers' struggle to reconcile their viewpoints on linguistics and information technology with their laboratory observations. On one end of the spectrum is the view that the "genetic code" is nothing of the kind; rather, it is a metaphor for biological specificity. At the other end of the spectrum is the view that the "genetic code" is actually the language for life, complete with all of its spiritual and scriptural qualities.

Kay, judging from her thesis statement in chapter 1 as well as her discussion in the conclusion, is a supporter of the first view. In a sense, her view, or others' for that matter, should not really matter. Whether one believes that the genetic code is a representation of the "Word of God" or that it is merely a representation for the biological specificity necessary for life, this belief does not change what it is. In the process of learning about or trying to understand something, we naturally liken things to one another. We relate the unfamiliar to the familiar and then document the differences. "'This' is like 'that' except for the following differences."

Thus, in trying to understand how a section of DNA relates to a specific protein, some researchers found similarities to a code, while others found similarities to a language, and others found similarities to neither. What I have to take issue with is Kay's assertion that DNA does not really contain information; rather, it represents biological specificity. In her conclusion, she argues for this by pointing out that despite our knowledge and understanding of the genetic code, science has been largely unsuccessful in understanding what we have read: being able to distinguish coding and non-coding sequences, being able to sort out the plethora of polygenic disorders, and finding any true promise in the field of gene therapy. This philosophy smells too much to me like that of the creationist: "Life (or some feature of it) is too complex to have evolved on its own. Therefore God (or some other designer) must have designed it." Kay seems to be arguing that because today we do not have all the answers, because we are not "fully literate in the language of DNA" (to use a different metaphor), that DNA does truly contain information.

In my opinion, DNA does contain information, information that directs a cell in how it should operate and behave. Today, when given an mRNA sequence, computer programs without the aid of human intervention can read that sequence and give the amino acid sequence of the resulting protein. Additional progress has been made in identifying signals for intron-exon junctions, transcriptional start and stop sites, and other regulatory signals. Today, our understanding of these sequences, this DNA information, is incomplete. Our understanding is even more limited when we consider the global landscape of the genome. How does a cell know which regions of the genome to leave active, while silencing others? How is development regulated? We understand that there is a dizzingly complex series of feedback loops, where DNA, RNA, protein, carbohydrates, fats, and a variety of small organic molecules all interact for the survival or death of the cell, tissue, organ, and organism. The information for these interactions, the instruction set, is all contained in the DNA. Our knowledge and understanding of this information is currently imperfect and incomplete. The complexity that results from the interactions between the cellular (and extracellular) components makes it difficult to tease out the necessary signals and information. This results in a "chicken or egg" sort of paradox. Again, regardless of what one's view is, it does not change the way things actually are. To deny that DNA contains information, based on our current inability to use it to describe life, is simply shortsighted.

In the end, I cannot recommend this book. Although I am impressed with the thoroughness and completeness of her research, I find that the process of bringing these ideas together has resulted in text that is unnecessarily dense and that ultimately falls far short of the promise inherent in this naturally compelling story.

This version might differ slightly from the print publication.