On October 5, Keith Campbell—one of the scientists who worked on Dolly the sheep, the first mammal cloned from an adult cell—died at the age of 58.

Adult cells have specialized jobs. They make one thing—skin, for example. Embryonic cells are not specialized. So, making an entire body from an embryonic cell is relatively easy. Making an entire body from a specialized cell is not. Campbell suggested trying to find a way to get adult cells to revert, to forget their specialization. Starving the adult cell did the trick. Dolly followed.

Some people call cloning “playing God.” Mostly, those people are talking about human cloning, not animal cloning.

But, still, Dolly caused a stir. And accusations of playing god. READ MORE >