The researchers stopped well short of creating a human clone. But they showed, for the first time, that it is possible to create cloned embryonic stem cells that are genetically identical to the person from whom they are derived.
These stem cells could go on to differentiate into heart, nerve, muscle, bone and all the other tissue types that make up a human body.
Since the birth of Dolly the sheep in 1996, researchers have cloned about 20 species, including rabbits, goats, cows and cats. Yet they have been unable to create biologically identical copies of any monkey or primate, including humans, possibly because their reproductive biology is more complicated. Read more >>