Identical long-tailed macaques Zhong Zhong and Hua Hua were born several weeks ago at a laboratory in China. Scientists say populations of monkeys that are genetically identical will be useful for research into human diseases. But critics say the work raises ethical concerns by bringing the world closer to human cloning. Qiang Sun of the Chinese Academy of Sciences Institute of Neuroscience said the cloned monkeys will be useful as a model for studying diseases with a genetic basis, including some cancers, metabolic and immune disorders. There are a lot of questions about primate biology that can be studied by having this additional model," he said.

Tags: Monkeys, animal, animals, clones