Who spearheaded the groundbreaking team that achieved the first successful cloning of a mammal?

The cloning of Dolly the sheep in 1996 at the Roslin Institute in Scotland was a monumental achievement in biological science. Before this, cloning complex mammals from adult cells was considered largely theoretical. The key breakthrough was a technique called somatic cell nuclear transfer, where the nucleus of an adult cell is transferred into an egg cell that has had its own nucleus removed. This reconstructed egg is then stimulated to divide and develop into an embryo. While many scientists contributed to this effort, Sir Ian Wilmut and Keith Campbell led the team that successfully brought Dolly to life. Wilmut is often the more recognized name, but Campbell's contributions were equally vital, particularly in refining the cell culture techniques that made the cloning possible. The other names listed are associated with different achievements: Patrick Steptoe was a pioneer in in-vitro fertilization, Jayne Torvill is a famous ice skater, Mary Peters is a track and field athlete, John MacLeod was a hockey coach, and James Goodfellow invented the personal identification number (PIN).