After Dolly

by Ian Wilmut and Roger Highfield

Cloning tends to elicit the kind of hysteria usually reserved for boy bands, movie stars and serial killers. Dolly the sheep was an entirely different breed of celebrity. Cloned from the mammary gland of a 6 year-old ewe by scientists at the Roslin institute this gregarious sheep had no particular talents, but her mere survival made her important. This book tells the story of her life, and what her remarkable birth and that of other lab-produced creatures means for science and humanity.

Although Roger Highfield is credited as an author the book is written entirely as Ian Wilmut's partly biographical account. Wilmut gives the impression of a mild-mannered, rational scientist faced with an outbreak of madness when the brash, pushy and ignorant media got hold of Dolly's story and squeezed it for all the juicy drama they could. Whether this is accurate is open to debate, but he ca certainly quote some very silly headlines from the time. The announcement of Dolly's birth also led to a spate of cultists and frauds who made wild and false claims about reproductive technologies. Then there are the people who object to this research on religious and ethical grounds, and the delays this causes when certain types of experiments are banned.

The story of reproductive cloning begins decades earlier than many people realise. Ian Wilmut explains the history of embryology, particularly during the 20th century. It's an entertaining, accessible and often surprising account. The authors slip in more technical concepts quite gradually, so the end of the book deals with fairly advanced stuff but you get there without the sense of having made any effort.

Dolly's cloning wasn't the same as the popular idea of creating an exact copy of another animal, which remains a long way in the future if it's ever going to be possible. Things like gene expression and mitochondrial DNA stand between scientists and the goal of making perfect copies of a creature. The beginnings of life are very complex and delicate, and just how delicate is drummed home by the tales of frequent failures. long hours and difficulties working with tiny eggs. Ian Wilmut explains how poorly understood embryology remains. There's a lot of detail about the potential dangers of mucking about with the start of life, from the high failure rate of pregnancies to the possibility of abnormalities. The book makes a very clear case against cloning human babies, taking in the diverse social implications as well as the limitations of current technology. It's a persuasive argument as well as an informative work.

Although Ian Wilmut is opposed to cloning human babies, he's very much in favour of what is termed therapeutic cloning. This involves using blastocysts to work on cures for a range of human diseases. Blastocysts are early embryos in the first 14 days of life, when they are little more than a lump of cells without even the precursor to a nervous system that would allow them to feel pain or think. He offers clear and convincing reasons for where he draws his ethical lines, based on what we know about human development.

There's a sense of enthusiasm running through After Dolly that makes you want to pick up a microscope and study cells. It's not a wide-eyed optimism based on fantasies of perfect people and miraculous breakthroughs within easy reach. Rather, the book is full of a well-informed zeal for a field that could eventually have very useful medical applications. There's discussion of pharming, which means modifying animals so they can produce drugs in their own bodies to alleviate various human illnesses. The book also covers gene therapy, stem cell research, what embryology teaches us about ageing and cellular clocks, efforts to make chimeras, and more. It's tantalising because the cell contains the secrets of the rejuvenation and immortality of our species, and as Dolly the sheep proved this applies to every cell, not merely eggs and sperm cells.

Ian Wilmut labours the point about his ethical stance somewhat during the final chapters of the book. Nevertheless this is a fascinating examination of an area of research that's only just beginning to give up its secrets.