We Should Take the 'Posthuman' Era Seriously (Martin Rees)
Humanity will soon itself be malleable, to an extent that's qualitatively new in the history of our species. New drugs (and perhaps even implants into our brains) could change human character; the cyberworld has potential that is both exhilarating and frightening. We can't confidently guess lifestyles, attitudes, social structures, or population sizes a century hence. Indeed, it's not even clear for how long our descendants would remain distinctively 'human'. Darwin himself noted that "not one living species will transmit its unaltered likeness to a distant futurity". Our own species will surely change and diversify faster than any predecessor -- via human-induced modifications (whether intelligently-controlled or unintended), not by natural selection alone. Just how fast this could happen is disputed by experts, but the post-human era may be only centuries away.