Who was Dolly the sheep?
Carl Sagan
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Dolly was the first mammal cloned from the DNA of an adult animal: She was a Finn Dorset sheep born in 1996 and was hailed as a monumental scientific breakthrough when her birth was announced in early 1997. Scientists at Scotland’s Roslin Institute used somatic cell nuclear transfer (SCNT), a reproductive cloning method, to produce the lamb, which carried the same nuclear DNA as the donor sheep (the cells were taken from the donor’s udders). Dolly made headlines around the world and launched a public debate about the possibilities—and ethics—of cloning. Over the years, research groups around the world reported the cloning of mice, rats, cows, goats, rabbits, pigs, a horse, a mule, and a dog.
In 2003 Dolly was put to sleep. Though she lived only about half the expected 10-to 12-year life span for a Finn Dorset sheep, scientists who conducted a postmortem examination of her found that other than her ailments (arthritis and lung cancer), she appeared to be normal. The celebrity sheep was the mother of six lambs, which were brought into the world the old-fashioned way.