If humans don't watch out, computers will take over the Earth, says Stephen Hawking.
Since computers double their capacity every 18 months, there's a real danger they will develop intelligence, the Cambridge University physicist told the German news magazine "Focus," which published the interview in its Monday edition.
Hawking's comments, reminiscent of the scenario in Stanley Kubrick's science fiction film "2001: A Space Odyssey," were published along with an introduction to his forthcoming book, "The Universe in a Nutshell."
Hawkings said scientists could deliberately change genetic material, increasing the complexity of DNA and thus improving humans.
It will be a slow process, because it takes around 18 years, or a generation, to determine the effects of genetic manipulation, he said.
It is vital to develop ways of keeping biological systems superior to electronic ones, Hawking continued. Humans must develop an interface that allows the human brain to be directly connected to a computer, so that the artificial brain contributes to human intelligence, rather than opposing it.
Hawking, who has the neurological disease Amyotrophic Lateral Sclerosis (known in the US as Lou Gehrig's disease) -- uses a motorised wheelchair and communicates with the aid of a portable computer and speech synthesiser.
Stephen Hawking's Web site is http://www.hawking.org.uk/.