Ten years after introducing the world to Dolly the sheep, the first cloned animal, University of Edinburgh biologist Ian Wilmut announced last November that he was quitting the cloning game. He was not going out on a high note-neither Wilmut nor any of his colleagues had succeeded in cloning an adult human cell by implanting its nucleus into a properly prepared egg, yielding precious embryonic stem cells. Rather his announcement heralded the publication a few days later of a method for directly transforming human skin cells into a form that was essentially equivalent to the embryonic kind. Cloning, Wilmut told reporters, had become obsolete.
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