In the interview, called Our Cosmic Self-esteem, Rees describes how humans may start to change in radical ways within single generations under its own guidance. "If this future plays out," says Rees, "the future itself becomes more difficult to forecast."
Aware of the tremendous time span lying ahead of us, Rees notes that "most educated people are aware that we are the outcome of nearly four billion years of Darwinian selection, and I think many tend to think humans are the culmination of all that. But astronomers know that our sun is less than halfway through its life span. Our sun will flare up and die six billion years from now, a period of time longer than the sun's history so far." Some people imagine that there will be humans watching the sun's demise six billion years from now, he says, "but any creatures that exist then will be as different from us now as we are from bacteria or amoebae."
He notes that we are likely still in the early stage of the emergence of complexity and intelligence. Rees admits that it's hard to imagine what forms future intelligent life might take, but that we should consider ourselves as nowhere near the culmination of evolution.
Despite warning of possible existential catastrophies this century, he believes that on optimisitc scenario sees human communities spread beyond the Earth for the first time. "Self-sustaining groups established a hundred years from now would not be destroyed whatever happened to the Earth. That could be the first step towards evolution beyond the Earth," he says.
Rees, a believer in accelerating change, notes that not only are traditional technologies changing faster than ever, but the world is changing in different ways and that humans themselves are going to change. "For several thousand years," says Rees, "the one thing that hasn't changed has been human nature and the human physique. But in this century we have targeted drugs, genetic manipulation, and maybe even implants in the brain."
Consequently, he notes
[T]his makes it harder to predict a hundred years into the future than it would have been for someone in 1900 to predict our present-day world. That suggests there are greater uncertainties and greater risks facing us now. But it also suggests that if humans did establish groups beyond the Earth, then it wouldn't take more than a few centuries at most before they evolve into different species. They would be able to use genetic techniques to adjust themselves to survive in a very alien habitat.As usual, Martin Rees has very interesting things to say, but I often feel that he's holding back in his writings and speculations. I sometimes get the feeling that he's academically straight-jacketed, afraid to speculate too far outside the box for fear of being ostricized by more conservative elements. I'm sure he has some pretty specific ideas about what posthuman and postbiological intelligences could look like and the kind of activities they could engage in. If I'm right, hopefully he'll find the courage to let us in on some of his insights in the future.
Otherwise, one gets the distinct impression that he's taking advantage of his public presence and merely riding on the philosophical and futurological coattails of the various transhuman thinkers who have been discusing these possibilities for years.