image: Members of the original research team who cloned Dolly the Sheep, the first animal cloned from an adult cell, gathered to celebrate her 20th anniversary yesterday with a sheep-shaped cake. From left to right: Dougie McGavin, John Bracken, Professor Sir Ian Wilmut, Lesley Penny. Dolly's birth proved that cells from anywhere in the body could be made to behave like a newly fertilised egg -- something that scientists previously thought was impossible. The breakthrough paved the way for researchers to develop methods of producing stem cells from adult cells, offering hope of therapies for a wide-range of diseases. view more
Credit: University of Edinburgh/ Maverick Photo Agency