But Dolly lives on. Her leftover sample of tissue has remained in the freezer all these years later, and now four exact replicas carry her DNA. 

Campbell cloned the Dollies to see if improvements made to the cloning technique prevented the health problems that Dolly suffered within the new sheep. So far, Campbell says the Dollies are doing fine and that they are being watched very closely. 

The Dollies are already three and a half years old, but Campbell did not mention their existence until a recent lecture at the European Parliament debate on cloning and animal welfare. He is looking to publish further detail on the Dollies in a scientific journal, noting that the cloning technology is improving but not yet perfect.