The ‘secret of life’ isn’t reducible to DNA
HOW LIFE WORKS A user’s guide to the new biology
PHILIP BALL 560pp. Picador. £22.
PHILIP BALL’S NEW BOOK opens on June 26, 2000, the day President Bill Clinton announced the completion of the first-draft sequence of the genome of a single human. At the time, it was hoped that this would usher in a new era of gene-targeted medicines – magic bullets to shoot down cancer or diabetes. The hope was misplaced. More than two decades later, we are still waiting for these revolutionary therapies. Hundreds of thousands of genomes have now been sequenced, but hardly any medical advances have been developed as a consequence.
Why did the genome fail to deliver? The answer is that life turned out to be more complicated than the sequencing pioneers imagined. A conceptual earthquake has radically shifted the gene paradigm underpinning biology since the early twentieth century, and facing up to the “new biology” of this book’s subtitle requires “a shift in the notion of what life … is”.
Ball is a former editor of Nature and, though a physicist himself, has read a lot of biology papers. He admires those biologists who have managed to “wrestle any insights at all into what living matter is and how it sustains itself ”. The experience has nevertheless filled him with misgivings about the process by which the science of “genes, cells, evolution and us” passes beyond the reach of academic journals into public discourse, where it is too often “dangerously simplistic and out of kilter with what we know”. Ball aims to address these shortcomings with a new vision of biology.
How Life Works: A user’s guide to the new biology opens with an attack on the metaphor of living cells and organisms as machines, an idea that goes back to Descartes. Ball refutes it, comparing the rigidity of machines with the flexibility and robustness of living organisms, and embracing the idea that living organisms can have meaning and purpose – something machines so far lack. In the second chapter, “Genes: what DNA really does”, Ball takes on American biologist James Watson and English physicist Francis Crick and their claim, in 1953, that the unravelling of the double helical structure of DNA and its genetic coding properties amounted to a discovery of “the secret of life”. The idea that life has some kind of secret essence isn’t new, and Ball doesn’t dispute the basic principles of the genetic code, but he insists that the idea of a one-to-one relationship between genes and phenotypes – the heritable observable characteristics of living organisms, such as eye colour or height – is just plain wrong.
The following chapters provide a detailed account of how our current understanding of genes, cells,
