On July 5, 1996, Dolly the sheep became the world’s first ovine (sheepy) superstar.
She was the first mammal successfully cloned from an adult cell, ushering in an era where you can special-order cloned puppies or elite polo horses.
But scientists were also concerned that Dolly could be a cautionary tale: genetic testing revealed that her DNA showed signs of aging at just one year old, and at five, she was diagnosed with arthritis. It wasn’t clear whether Dolly’s problems were because she was a clone.
Dolly eventually died after contracting a virus in 2003 at six years old – half the typical life expectancy of a sheep of her kind.