In February 1997, it was announced that the sheep, created by Scottish geneticist Ian Wilmut and the Roslin Institute, was the first successfully cloned adult mammal. TIME‘s March 10, 1997, cover story debated whether humans could and should be cloned in the same way. Applying the technique that made Dolly, scientists went on to clone dogs, cats and mice. Then in 2011, scientists created the first stem cells using adult human cells, and in May 2013, scientists announced they had created embryonic-stem-cell lines from human skin cells in just a few months. Veterinarians euthanized Dolly in 2003 after she developed a lung disease, and the National Museum of Scotland in Edinburgh displayed the sheep’s remains.