Cloned sheep still healthy after eight years
The four genomic "siblings" of Dolly the sheep, the first mammal to be cloned, are still healthy after eight years with no signs of rapid ageing, a study revealed. Some had early signs of osteoarthritis, which is normal for their age, scientists claimed. Dolly, born in 1996, had died aged 6.5 years, raising concerns over the safety of cloning animals.