The award of the 2007 Nobel prize in physiology or medicine to three gene technologists has been widely applauded by biologists. They believe that the three scientists' achievements will play a major part in revealing the extent of genetic influences in human disease.

Rather less enthusiastic is the animal rights lobby. The work for which Mario Capecchi, Martin Evans, and Oliver Smithies were awarded the prize led to the development of the quaintly but aptly named “knockout mouse.” Now an essential tool of laboratory research into the role of genes, its creation reversed a fall in the number of experiments carried out each year on animals.

The Nobel citation talks of the trio's discovery of “principles for introducing specific gene …