The birth of a sheep – even though we might all think of baby sheep as terribly cuddly and cute – is not of course usually the occasion for worldwide attention. But the birth of Dolly, in February 1997, was indeed a birth heard around the world because she represented an (at least then) astonishing breakthrough in research – the production of a new individual through the cloning of an adult mammal. Suddenly the world of cloning, which before had seemed to most people still very much belonging to the theoretical realm, became something possible and even likely. This paper examines cloning as representative of the borders of physiological research today as scientists attempt to recreate the complex physiology of mammals – something that was millions of years in the evolutionary making.
