“Whether or not rogue scientists could clone a human is hotly debated. After 6 years trying, on over 700 monkey eggs, Gerald Schatten of the University of Pittsburgh says not.

The current technique, his team conclude, robs primate eggs of proteins they need to survive. The ‘nuclear transfer’ procedure used to create Dolly the sheep “paralyses the egg”, Schatten says. Key proteins are sucked out when the egg is stripped of its DNA to be replaced with genetic material from another cell.” Nature