"Gradually, the truth dawned on me: that Man had not remained one species, but had differentiated into two distinct animals..."
H. G. Wells: The Time Machine, 1895
"In the future perhaps it may be possible by selective breeding to change character as quickly as institutions... We can already alter animal species to an enormous extent, and it seems only a question of time before we shall be able to apply the same principles to our own."
J. B. S. Haldane, Daedalus or Science and the Future, 1923
"But the likelihood is that, in 100,000 years time, we shall either have reverted to wild barbarism, or else civilisation will have advanced beyond all recognition--into colonies in outer space, for instance. In either case, evolutionary extrapolations from present conditions are likely to be highly misleading."
Richard Dawkins, The Evolutionary Future of Man, 1993
"On a time-scale of a thousand years... Our one species will be many. There is no reason why a variety of intelligent species should not fill a variety of ecological niches in different physical environments, some adapted to heat, other to cold, some to zero gravitiy, others to strong gravitiy, some to high pressure, others to living in the vaacum of space."
Freeman Dyson, Imagined Worlds, 1997
"if we could make better human being... why shouldn't we?"
James Watson, panel on human germline engineering, 1998