British scientist Ian Wilmut, who created the world's first cloned sheep, Dolly, has died. He was 79.
Wilmut, who studied embryology and regenerative medicine, cloned Dolly in 1996 from the cell of an adult sheep.
While the lamb's creation raised hope that the technique could be applied to treatment of incurable diseases, it also sparked controversy over the ethics of possible human cloning.
Wilmut continued to study ways to treat incurable diseases using clone technology, but gave up in 2007 after finding that research into induced pluripotent stem cells, or iPS cells, has greater potential and is more socially acceptable.
The study of iPS cells was being conducted at the time by a Kyoto University team led by Yamanaka Shinya.
Wilmut's death was announced on Monday by the University of Edinburgh, where he once taught.
The university didn't disclose when or why Wilmut died. But it did say he was diagnosed with Parkinson's disease five years ago.
British public broadcaster BBC said, "In retrospect, Dolly's birth was not the paradigm shifting moment that many hoped and/or feared it was at the time."
It added that Dolly the sheep marks an outstanding scientific achievement by Wilmut's team, which "sparked a revolution in medical research."