London - A Japanese veterinary scientist aims to use sperm buried in the Siberian permafrost to re-create the woolly mammoth that roamed the tundra there 40,000 years ago, Britain's New Scientist magazine said yesterday. It said Mr Kazufumi Goto of Kagoshima University believed the extinct animal could be reproduced by injecting DNA from the mammoth's sperm into the eggs of African elephants using in-vitro fertilisation techniques.