The Delphic Boat: What Genomes Tell Us

  • Antoine Danchin
, transl. Alison Quayle Harvard University Press: 2003. 368 pp. $35, £23.50, €35

This contribution from old Europe's grande nation discusses genomics, the politics of genome research, the philosophy of science, and the not-so-small question of the nature of life. The first problem faced by the author, Antoine Danchin of the Pasteur Institute in Paris, France, is how best to describe a genome. He borrows from Greek mythology the tale of the oracle of Delphi, which asked whether a boat that has had all of its planks replaced over time is still the original boat or not (to its owner, who watched its evolution, it would be). Danchin makes the point that it is the relationship of the planks (or in the case of the genome, the genes) to each other that determines what kind of boat (genome) it is; individual planks are less important in determining the essence of a boat.

It has been known for some time that a genome is not merely a set of independent genes arranged like pearls on a string. The essence of a genome has been described as a code, a blueprint, a musical score and a set of instructions. All of these metaphors are used in an attempt to convey the notion that a genome is more than the sum of its parts.

From an evolutionary biologist's point of view, each organism's genome (including our own) is a record of its evolutionary history: genomes are shaped by symbioses and hybridizations, as well as by natural selection. In attempting to understand the origin and diversification of life, the increase in complexity during ontogenetic development, and even more straightforward questions such as the genetic bases of diseases, the study of individual genes will reach its limits and fall short of a more holistic appreciation that considers the entire genome (and the entire phenotype). Genes 'talk' to one another, regulating each other's expression in response to environmental conditions and the prevailing ontogenetic or metabolic state of the cell or organism. Genes are also affected by their position in the chromosome, by the base composition of surrounding DNA, and by other “local climates”, as Danchin puts it, that might influence their tempo and mode of evolution or level of expression.

Early and overly simplistic notions that the determination of a genome sequence (or “genome text”, in Danchin's words) will determine precisely how an organism works have long gone the way of the dodo. In silico analyses — computer analyses of genomic information as an alternative to in vivo or in vitro studies — are now an established field, known as bioinformatics. They are largely based on comparative (evolutionary) approaches. The hardest route, but in my opinion the one that offers the brightest future and the most intellectual profit, might be comparative and functional-genomic analyses of the architecture of genetic cascades and networks. The hope, and there are encouraging signs for this, is that there are commonalities and higher-level organizational principles, or even that this field of enquiry might reveal some of biology's more elusive laws.

Of course, no book can be written for everybody, but many readers might like to know what, if anything, genomics can tell us about the meaning of life. Various features of this book will be of varying interest to different audiences. Given the big issues it addresses, The Delphic Boat is apparently intended for a wide, non-specialist readership. Descriptions of the idiosyncrasies, foibles, imperfections and particular aspects of the politics of French grant-funding agencies make the book a lively read and demonstrate to the uninitiated reader that politics has an unpleasantly large role in science. Danchin also stresses the important contributions of French researchers to the various advances in genomics.

Although these often rather personal and historical sidelines might be of particular interest to science historians or researchers working on microbial genomics, these specialist readers would not want to be bothered with explanations of how the polymerase chain reaction works, for example. But such techniques and other introductory and background information will presumably be of interest to the non-specialist reader who would like to discover what genomics is all about. This kind of reader might need more explanation of some of the basic concepts in genetics and genomics, however. In some places, rather specific jargon is used which might confuse general readers. And discussion of alternative DNA-sequencing techniques is probably beyond most uninitiated readers. 'Automatic' sequencing techniques have been used pretty much exclusively in genomics for 15 years now, but one of the few figures in the book shows a 'manual' gel with radioactively labelled DNA — rather a relic of the past. The lay reader would have profited from the inclusion of an electropherogram instead, if the budget had stretched to colour figures.

These limitations aside, Danchin provides an authoritative and impressively multidisciplinary treatment of many aspects of genomics, and his provocative thinking about the raison d'être captured my interest. I suspect that it will do the same for many readers from a large number of scientific disciplines, not only biological ones.