THE OUTSPOKENNESS OF James Watson, co-discoverer of the double helix of DNA in 1953, has made him a star. Crowds jam his lectures to hear what Jim will say next. In public he has claimed that fat, dark people have better sex than thin, white ones. In Germany he has castigated scientists for their timidity in genetic research because of Nazi eugenics policies. In India he said that environmentalists who oppose the genetic modification of crops should walk into the sea.

Is this indifference to what others think related to the gift for discovery? In his new book, the writer David Ewing Duncan asks about the role of personality in science. Can we trust the geniuses — his word — who are pushing into unknown territories of gene mapping and modification? Are they delving into mysteries “perhaps better left to God”? An interesting book; pity about the title. Ewing Duncan subscribes to the Mary Poppins school of science writing — you need spoonfuls of sugar to make the medicine slide down. We are fed lots of “excitedly, waving long, graceful fingers as her words spill out” and “skinny with paper-thin skin and his high whiny voice” (Watson). We also get reams of family background. The earthiness of Francis Collins, the head of the US National Genome Research Institute, “undoubtedly results from growing up on his parents’ 95-acre farm near Staunton, Virginia”. Undoubtedly? Hmm.

Sugar-coating may be needed, however, for the science involved is not easy for the layperson — one reason why phrases such as “Frankenstein foods” have such a hold on the public imagination. What excites the scientists in this book are the new directions opened up by the mapping of the human genome — the array of genes housed in the 23 pairs of chromosomes in every cell. Can they find the hereditary basis of disease? Can they alter faulty genes to restore health? Douglas Melton, a Harvard embryologist, frankly admits that he is motivated by a wish to cure his children’s diabetes. Melton is a fervent opponent of President Bush’s severe restrictions on government-funded research on stem cells taken from human embryos.

Where might research now lead? To a cure for cancer and Aids? To a mortal lifespan of hundreds of years? Or to laboratory-created organisms that might run out of control and turn on us? Ewing Duncan jokily conjures up visions of centaurs or, worse, a race of Schwarzeneggers. A more considered possibility comes from the distinguished microbiologist Sydney Brenner. We might learn “the answer to what it means to be human”.

The geneticist of the book’s title is an Icelander, Kari Stefansson. He not only plays basketball with the author (hence the “hoops”), he also leads Iceland’s project to make a database of the genetic details of the 680,000 people who have lived there since the 9th century. Ewing Duncan, as a brave investigative journalist, gave Stefansson a sample of his own DNA and waited uneasily for the analysis: predisposed to stroke, he should not drink.

James Watson, whom he calls “an obnoxious, dazzling personality”, has a one-word answer to account for his achievements: ambition. But these also reveal another component of the successful scientist: the ability to organise. Watson has made Cold Spring Harbor on Long Island a world centre for research. He also instigated, and for a time led, the US Government’s Human Genome Project to map and sequence the human genes. His tenure came to an end in 1992 after a row with Bernadine Healy, director of the National Institutes of Health.

Ironically, Watson, a passionate atheist, was succeeded by Francis Collins, a guitar-playing Christian who sang This Genome is your Genome at the party following the joint publication of results by the two genome project rivals in 2001. Collins, still in his post, believes that the human sense of right and wrong is the work of God and that genetic engineering is akin to Christ’s mandate to heal.

This book offers one example of how scientists can rein in their research. With a kind of DNA called “recombinant”, because it contains the fusion of two different species, they call a halt until rules can be agreed for its safe handling. The summary of the dispute about recombinant DNA is clear and helpful.

In his conclusion Ewing Duncan decides that we probably can trust scientists. They seem not to be Frankensteins but Einsteins. Their fascination is not with evil nor power but rather with something much harder for ordinary mortals to understand — the molecular biology of the gene.

THE GENETICIST WHO PLAYED HOOPS WITH MY DNA: The Quest to Rewrite Life
by David Ewing Duncan
Fourth Estate, £20; 273pp
£18 (free p&p) 0870 1608080
www.timesonline.co.uk/booksfirst

What's more...

THE DOUBLE HELIX
by James Watson (Penguin)
Account of the discovery of the structure of DNA.

ROSALIND FRANKLIN: THE DARK LADY OF DNA
by Brenda Maddox (HarperCollins)
Could Watson have done it without this young scientist?

THE SELFISH GENE
by Richard Dawkins (Oxford)
Eminently readable book about gene-building. What’s more ...

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