The scientific breakthrough, announced on this day in 1997, proved that geneticists could clone an adult mammal, giving rise to a new era of ethical debate and experimentation ...

The four sheep cloned from Dolly’s cell line did not suffer the same bad health as their sister, Dolly. Sheep live an average of 10 to 12 years, and these four — Daisy, Diana, Debbie, and ...

To shed light on the issue, University of Nottingham developmental biologist Kevin Sinclair and a team of veterinarians undertook a new analysis of Dolly’s skeleton, comparing it with the bones of her ...