Mammoth to be back again?

The pioneering scientist who created Dolly the sheep has outlined how cells plucked from frozen woolly mammoth carcasses might one day help resurrect the ancient beasts.
The notional procedure was spelled out by Sir Ian Wilmut, the Edinburgh-based stem-cell scientist, whose team unveiled Dolly as the world's first cloned mammal in 1996.
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 feat, Wilmut said in an article yesterday for the academic journalism website, The Conversation.
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.
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.
"I've always been very sceptical about the whole idea, but it dawned on me that if you could clear the first hurdle of getting viable cells from mammoths, you might be able to do something useful and interesting," Wilmut told the Guardian.
In his article for The Conversation, Wilmut explains the formidable hurdles that stand in the way of scientists who want to clone the beasts.
The technique requires scores of healthy mammoth cells and hundreds or thousands of eggs from a closely related species, such as the Asian elephant.
The most immediate problem is that mammoth cells must survive with their DNA intact. In practice, they degenerate quickly at the temperature of melting snow and ice, when most remains are found.
If good-quality cells can be extracted from mammoth remains, they could be reprogrammed into stem cells using modern procedures. These could then be turned into other kinds of cell, including sperm and eggs.
But the scientist said it could be 50 years before the techniques for resurrecting the woolly mammoth were perfected.