When the Roslin Institute's first sheep cloning work was announced in March 1996 the papers were full of speculation about its long-term implications. Because of this discovery, the medias attention has focused mainly on discussion of the possibility, of cloning humans. In doing so, it has missed the much more immediate impact of this work on how we use animals. It's not certain this would really lead to flocks of cloned lambs in the fields of rural America, or clinically reproducible cuts of meat on the supermarket shelves. But it does force us to ask questions about the way we are using animals with new technology, and the kinds of assumptions we make. To create Dolly (the cloned sheep), Scottish researchers simply took an unfertilized sheep egg and removed its genetic material. They then placed the empty egg in a dish with a cell from an adult sheep's udder, which contained a full complement of the adult sheep's genes. Finally the scientists applied an electric spark, which caused the two cells to fuse and begin dividing. The embryo was then transplanted into the womb of a surrogate mother to grow. The original aim of Dr Wilmut's nuclear transfer work was to find better ways to make genetic modifications in animals, by growing live animals from cell culture. It is very possible that cloning was only a side effect of the investigation and not what was supposed to be the center of this research project. But the ability to clone opens up a range of questions of its own. We can already do it to a limited degree by splitting embryos, without ethical concerns. It has been practiced only to a very limited extent, mostly in cattle. At the moment there is only one set of results in one breed of sheep, and rather little is understood of how it has happened. Different farm animal species differ quite markedly in embryological interventions like artificial insemination and embryo transfer. So it remains to be seen whether this same method woul...
