Sir Ian Wilmut, who cloned Dolly the sheep, has died

The embryologist kicked off a global firestorm in the mid-90s.

University of Edinburgh

Sir Ian Wilmut, the scientist who led the team that cloned Dolly the sheep in 1996, has died at 79. The University of Edinburgh, where he served as a professor before his 2012 retirement, announced his passing today. Dolly was the first successful cloning of a mammal from an adult somatic cell, demonstrating the viability of somatic cell nuclear transfer (SCNT). The controversial milestone helped pave the way for today’s research on regenerative medicine.

Born near Stratford-upon-Avon (also Shakespeare’s birthplace) in 1944, Wilmut discovered an interest in biology while at school in Scarborough; he later switched his major at the University of Nottingham from agriculture to animal science, kicking off the work he would be most known for. His Ph.D. studies at the University of Cambridge foreshadowed his later breakthroughs, focusing on “the preservation of semen and embryos for freezing.” In 1972, he became the first scientist to successfully freeze, thaw and transfer a calf embryo, which he called “Frostie,” to a surrogate mother.

Wilmut’s work at The Roslin Institute in Edinburgh continued to push the boundaries of animal genetics. He strived to create modified sheep that would produce milk with proteins that could treat human diseases. A year before Dolly, he successfully cloned two lambs (Megan and Morag) whose cells were taken from sheep embryos.

Portrait of Sir Ian Wilmut, the cloner of Dolly the sheep. The bearded man with glasses smiles for the camera over an off-white background.
Portrait of Sir Ian Wilmut, the cloner of Dolly the sheep. The bearded man with glasses smiles for the camera over an off-white background. (University of Edinburgh)

Dolly’s successful birth in 1996 marked the first time a mammal was successfully cloned from an adult cell. The scientifically groundbreaking announcement also set off a media firestorm as experts and casual observers wrestled with lab-made mammals’ ethical implications. Specifically, many wondered: If they’re doing sheep now, how long until they clone humans? Religious groups accused the researchers of “playing God.” Even those who focused more on the natural world than supernatural ones worried about the potential for making “designer humans” or something out of The Island of Dr. Moreau.

While Dolly proved that cells could be used to create a copy of the animal they came from, Wilmut’s next experiment proved that they could also be altered. Polly, born in 1997, was the first genetically modified cloned mammal. His team spliced the host’s genes with a human gene to create a sheep that would produce a protein missing from people with hemophilia. Polly was Wilmut’s last cloning experiment.

Wilmut moved to the University of Edinburgh the following decade, focusing on using cloning to make stem cells for regenerative medicine. He was knighted in 2008 and retired in 2012. Wilmut was diagnosed with Parkinson’s in 2018 and became a patron of a new research program at the university working to slow the disease’s progression with next-gen therapies.

According to The Guardian, Sir Ian is survived by his wife Sara, his children — Helen, Naomi and Dean — and his five grandchildren: Daniel, Matthew, Isaac, Tonja and Tobias.