Human genes in Polly clone
In 1997, the same Scottish scientists who produced the cloned sheep Dolly announced that they had cloned a sheep with human genes. Polly and four other cloned lambs mark a milestone in the effort to change the genetic makeup of animals. It is hoped that similar animals will eventually aid in human medicines, milk and organ transplantation, as well as medical research. PPL Therapeutics and the Roslin Institute near Edinburgh produce the transgenic animal born on July 9 Image: Polly the lamb carrying human genes with its Scottish black-faced surrogate mother.