Debunking DNA

Life Without Genes

Adrian Woolfson <em>HarperCollins, 420pp, £17.99</em>

ISBN 0002556189

In the beginning, God created Heaven and Earth. For too long this has satisfied most of us in the Christian world as an explanation for life on Earth. Other societies raised around transcendental-based creation myths had similar explanations. Today, the high priests of physics have supplanted the theologians as masters of all we survey.

And yet the events leading to the origin of life (however you define life) remain stubbornly elusive. Most scientists now agree that life evolved by natural selection of forms best adapted to propagate within their physical surroundings. The process of natural selection demands that each unit of life replicates with sufficient accuracy to retain the integrity of the species from one generation to the next. And yet perfect copies are of no use in a changing environment. A long-haired cow will survive better than a short-haired cousin if ambient temperatures were to fall. In order to generate diversity, enabling species to adapt to environmental change, replication requires an inherent, seeping instability, so that variations on the theme emerge constantly. Genes, made up from a code comprising the four bases of deoxyribonucleic acid (DNA), have been the perfect vehicle for both the propagation and diversification of life.

Most of us are happy to think of ourselves as living. Bacteria, with only several thousand genes, are also universally accepted forms of life. But can we say the same about computer programmes that can rewrite themselves, mutate and even spread to other computers? The ability to reproduce and propagate is insufficient to define the living state.

Adrian Woolfson has attempted to discuss and define life, with or without genes, in his new book, Life Without Genes. DNA-based replicators are almost certainly the descendants of earlier self-replicating units of ribonucleic acid (RNA). These, in turn, were more than likely the descendants of self-replicating units derived from materials other than nucleic acids.

It is fascinating to consider the early prehistory of DNA-based life on Earth. The view that an "RNA world" preceded our "DNA world" is now widely held among molecular biologists. Most agree that other organic or inorganic replicators must have preceded the RNA world. Computers and laboratory-based experiments have demonstrated the reality of chemical self-replication. Manipulation of self-replicating machines will provide the foundations of a revolution in "nanotechnology", which may underlie the next giant step in the economic progress of man.

In Life Without Genes, Woolfson has made a bold effort to bring some of these concepts to the general readership. But the problem is that few scientists can present their work with the elegant simplicity of, say, Richard Dawkins or Stephen Jay Gould. Many scientists, wedded as they are to precision, cringe when they are asked to disseminate their research to a lay audience. In taking novel concepts and abstract ideas into a more public domain, however, borrowing from poetic technique is indispensable.

In trying to rid himself of the shackles of scientific rigidity, Woolfson - a respected Cambridge scientist - has overcompensated. Deft comparisons can clarify complex notions, but crass similes devalue them; and Woolfson too often loses himself in a thicket of clumsy phrase-making.

But the public - told that genes rule supreme in the panoply of life - is entitled to know that DNA has not always been ascendant. It really is time to return to Erwin Schrodinger's seminal question: "What is life?" Woolfson has some interesting and profound thoughts hidden in his text. An index could have saved the book. Instead, we are left with no option but to follow the author into what he himself might describe as an impenetrable "hyperbole space".