Now scientists create a sheep that's 15% human

Scientists have created the world's first human-sheep chimera - which has the body of a sheep and half-human organs.

The sheep have 15 per cent human cells and 85 per cent animal cells - and their evolution brings the prospect of animal organs being transplanted into humans one step closer.

He has already created a sheep liver which has a large proportion of human cells and eventually hopes to precisely match a sheep to a transplant patient, using their own stem cells to create their own flock of sheep.

At present 7,168 patients are waiting for an organ transplant in Britain alone, and two thirds of them are expected to die before an organ becomes available.

But the development is likely to revive criticisms about scientists playing God, with the possibility of silent viruses, which are harmless in animals, being introduced into the human race.