The pioneering scientist who created Dolly the sheep has outlined how cells taken from frozen woolly mammoth carcasses might one day help resurrect the ancient beasts.
Though it is unlikely that a mammoth could be cloned in the same way as Dolly, more modern techniques that convert tissue cells into stem cells could potentially achieve the achievement, Wilmut says.
"I think it should be done as long as we can provide great care for the animal. We can learn a lot about them," he added.
Woolly mammoths roamed the Earth tens of thousands of years ago in a period called the late Pleistocene. Their numbers began to fall in North America and on mainland Eurasia about 10,000 years ago. Some lived on for a further 6,000 years. Their demise was likely the result of hunting and environmental change.
The prospect of raising woolly mammoths from the dead has gathered pace in recent years as the number of frozen bodies recovered from the Siberian permafrost has soared.
Earlier this month, the most complete woolly mammoth carcass ever recovered from Russia was unveiled at an exhibition in Yokohama, Japan. Samples have been sent to the laboratory in South Korean which, with Russian researchers, hopes to clone the mammoth.
Though Wilmut does not doubt the sincerity of the scientists hoping to clone woolly mammoths with the Dolly technique, he can see several problems like the fact that mammoth cells must survive with their DNA intact and cloning needs a female of a closely related species to provide eggs and to carry the pregnancy achieved with any cloned embryo.
The closest living relatives to mammoths are elephants, but because there is a danger of elephants becoming extinct, it is clearly not appropriate to try to obtain 500 eggs from elephants.
There is an alternative, though. If good-quality cells can be extracted from mammoth remains – and that is a big if – they could be reprogrammed into stem cells using modern procedures. These could then be turned into other kinds of cell, including sperm and eggs. Mice have already been born from sperm and eggs. This has already been done with mice.
But it could be 50 years before the techniques for resurrecting the woolly mammoth were perfected.
That gives time for scientists to work out some of other problems that would arise if a mammoth were ever born again.
