Nature: Scientist dreams of mammoth clone

Jurassic Park could have been the inspiration for a scientist who thinks the remains of behemoths that lived 10,000 years ago in Siberia can be brought to life through the agency of DNA and with the co-operation of African elephants. Charles Arthur, Science Editor, examines the evidence.

A Japanese scientist, Kazufumi Goto, believes mammoth carcasses buried for thousands of years beneath the Siberian permafrost could still have intact sperm and this could be recovered and the DNA used to inseminate African elephants, the mammoths' closest living relative.

But first you need a mammoth. For that the team is turning to David Smale, a geophysicist with the consulting engineers Mott McDonald, who will travel to Siberia next summer to use ground-penetrating radar, which can make out the size and shape of buried objects, to find mammoths which may have been trapped and frozen up to 40,000 years ago.

Woolly mammoths lived alongside humans and were widespread until the end of the Ice Age 10,000 years ago cut down their sources of food. Six have been found frozen in Siberia. According to New Scientist magazine, Dr Goto reckons that if any males are found, sperm DNA could be extracted, frozen and returned to Kagoshima University in Japan. He has already demonstrated that DNA from dead bull sperm can be injected into cows' eggs to produce viable cattle embryos. He believes the same system could also work for mammoths, using elephant eggs.

But Adrian Lister, of University College London, is sceptical. He points out that it needs a male carcass whose sperm DNA has survived non-medical freezing and thawing. "Everything we know about preservation of DNA in frozen tissues suggests it's smashed up into fragments," he told New Scientist magazine.

One thing that Tyrannosaurus rex never had to defend itself against in the past: poachers.

But a dinosaur graveyard in Montana is being guarded by the FBI on behalf of scientists who believe they may have unearthed the largest T rex skeleton but are also worried that greedy prospectors may try to steal the bones, which can command thousands of dollars from collectors.

The site of the find is in Hell Creek, in eastern Montana, which has a geological formation that makes it famous for preserving dinosaur bones. But according to Keith Rigby, of the University of Notre Dame, when the site was identified as a dinosaur site, its former owners began digging up bones, including the skull, apparently to sell them to a private collector.