Cloning of the lamb Dolly, the first mammal to be cloned from an adult cell. Her birth established that the nuclei of at least some adult cells can be used to produce sheep or other animals that are genetically identical to the donor, when transferred into eggs from which the genetic material has been removed. Wilmut led the team that created Dolly but credits his colleague Keith Campbell with "66 percent" of the invention that made Dolly's birth possible. Co-authored by A. E. Schnieke, J. McWhire, and A. J. Kind.