Jacob鈥檚 Ladder: The history of the human genome by Henry Gee, Fourth Estate/W. W. Norton, 拢20/$25.95, ISBN 1841157341/0393050831
IF YOU believed the hype, the sequencing of the human genome would finally tell us how babies come from fertilised eggs and, more generally, what it is to be human. Henry Gee, very sensibly, doesn鈥檛 buy it. It is not that the sequencing of the human genome is not a major landmark. It is just that the sequence of As, Cs, Ts and Gs in themselves will not tell us that much about ourselves.
What is the origin of the idea that the answers would fall out of the genome? Gee entertainingly traces the history of biology from Aristotle through the medieval and Renaissance embryologists, via late 18th and early 19th-century philosopher-biologists through to Darwin and the early geneticists. Taking this refreshingly long view, Gee points out the striking resemblance of the assertions regarding the importance of the human genome to some of these early ideas. The force of the argument in Jacob鈥檚 Ladder is possibly weakened, however, when you realise that, while the earlier workers may actually have believed what they were saying, in the case of the genomicists it was only ever puff.
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If the sequence alone is not the answer, how then will we come to understand human development? Very much up with the current vogue, Gee argues that analysis of the network of interactions between gene products and genes is the way ahead.
But will this approach, what is now known as 鈥渟ystems biology鈥�, deliver the goods or will this be just the latest oversold idea? Gee rests much of his case on just one computational analysis showing that, for a given network involved in fruit-fly development, you can bash it about quite a bit but it still gives the same results.
It is marvellous that we can now create mathematical models that actually describe complicated biological phenomena, but are they all necessarily robust, as Gee seems to suppose? Recent analyses of the network of proteins involved in yeast metabolism suggest not. So while some of Gee鈥檚 far-reaching discussions rest on shallow foundations, I very much agree that we will be hearing much more of systems biology. And that isn鈥檛 just hype.