THE human race is likely to be wiped out by a virus before the end of this millennium unless space colonies are built as an escape route, famed cosmologist Stephen Hawking warned in an interview on Tuesday. He told the Daily Telegraph he thought biology — rather than the threat of nuclear Armageddon — was the biggest challenge facing Mankind. “Although September 11 was horrible,” he added, “it didn’t threaten the survival of the human race like nuclear weapons do. In the long term, I am more worried about biology,” he said. “Nuclear weapons need large facilities, but genetic engineering can be done in a small lab. The danger is that either by accident or design, we create a virus that destroys us.” The solution? Expanding into space. “I don’t think the human race will survive the next thousand years unless we spread into space,” said Hawking, most famous for his bestselling “A Brief History of Time.”