Genetic twists of fate, by Stanley Fields and Mark Johnston, Cambridge, MA, MIT Press, 2010, 222 pp., £18.95 (hardback), ISBN 978-0-262-01470-0
A genetics text that is not a genetics text
At a time when whole genome sequencing and personal genotyping are waiting just around the corner, one of the important challenges facing the geneticist is to make the concepts and the results of his or her research understandable to laypeople. Probably equally challenging is the task of getting a broad range of people to actually take the time to read about DNA and its workings; hard to digest genetics texts are not many people's favorite bedtime reading. With their book Genetic twists of fate, Fields and Johnston try to address both these challenges, and they do so in an innovative way.
The innovative element of the book lies in the fact that the authors, both renowned geneticists, are not just relying on the classical tools of representation to illustrate the complex topics at hand. Even though Genetic twists of fate contains helpful illustrations and makes extensive (and a little laborious) use of analogies, the authors bring in yet another element: they present a wide range of stories about people – be it celebrities or ordinary citizens – whose lives have been dramatically affected in different ways by small changes in their DNA. These stories form the backbone of the book.
Importantly, this does not mean that the book is just an accumulation of drama – the basic goal of the authors remains to tell the reader “what genes are and how scientists track them down.” Therefore, Genetic twists of fate covers all the topics that one would also find in an undergraduate textbook on genetics. Fields and Johnston introduce the concept and the chemistry behind genes and proteins, they talk about the basics of regulated gene expression, dominant and recessive alleles, meiotic recombination, cancer and evolution. They explain how one cell can develop into a multi-cellular organism and what gene therapy is. Also – and this is a very important achievement of this book – the authors manage to explain the methods that scientists use to learn about genes and the roles they play in a way that is understandable to lay publics. This is something that, in my opinion, few popular genetics books manage to achieve.
But what, then, is the role of the personal stories, if the book is basically a genetics textbook? One might expect that the stories, focusing on individuals, serve to show the complex and context-dependent nature of our genetics and by that help to illustrate the many intermingled factors that can influence our development. But this is, unfortunately, not the case. The authors use the stories almost exclusively as “desserts,” i.e. as a means to attract people's attention (as the authors put it in the preface to the book: “all of us are tantalized by stories about real people […]”). Admittedly, the stories might serve this purpose quite well. But I think that, by reducing the stories to this role, the authors miss out on an opportunity to take their discussion of genetics to a more complex level, a level that would have been more in keeping with the current discussions in molecular genetics.
Instead, the authors stick to a strong genetic determinism throughout the book. To be fair, they do not defend a naïve “one gene-one phenotype” model, and they do acknowledge that both nature and nurture can affect our “behavior.” But the actual disputes about how to define a gene or how to understand gene regulation, which have become so pressing due to the discovery of processes such as histone acetylation, DNA methylation, or RNA editing, are completely absent from this book. The very fact that there are heritable changes in gene function in the absence of changes in the DNA's sequence is simply not mentioned and the word “epigenetics” does not appear once in Fields and Johnston's account of what genes are and how they work.
This creates a very one-sided view of “the” gene, and the lack of critical and more sophisticated discussion of the concepts and findings of current genetics is certainly the biggest weakness of this book. However, despite this limitation, Genetic twists of fate is an enjoyable and entertaining read that will allow people to get a first understanding of what researchers mean when they talk of “genes,” “heredity,” “point mutation,” or other concepts that they are introduced to by Fields and Johnston. This can certainly serve as a starting point for the reader to enter into a more nuanced discussion of the concepts and models proposed by geneticists.