Has science moved a step closer to producing human clones? The question has been raised after scientists in China produced two genetically identical monkeys. Zhong Zhong and Hua Hua are the first primates to be cloned using the DNA-transfer technique which produced Dolly the Sheep 20 years ago. Populations of genetically identical monkeys are now expected to be created to help with future research into human diseases. Campaigners however fear this is a step towards human clones and have hit out at the research. Activists also claim the tests involve unacceptable cruelty to animals. Dolly made history in 1997 after being cloned using somatic cell nuclear transfer, which involves transferring cell nucleus DNA to a donated egg cell that is then prompted to develop into an embryo. Sheep, cattle, pigs, dogs, cats, mice and rats have all been cloned with this method, but this is the first time a monkey has been cloned using this technique.