In October 2004 the bimonthly magazine Foreign Policy published a special report with the title, The World's Most Dangerous Ideas. Eight prominent thinkers were asked to reply to the question: "What ideas, if embraced, would pose the greatest threat to the welfare of humanity?" Francis Fukuyama responded with an essay entitled "Transhumanism." By "transhumanism" he was referring to a current of thought, gaining prominence in the past fifteen years, committed to using science and technology to transcend the limitations of human nature. Scientific research traditionally has striven to overcome the effects of human disease and degenerative illnesses -- purposes broadly therapeutic in nature. Transhumanism aims to move beyond therapy to enhancement. "Its proponents," to quote one advocate, "argue for a future of ageless bodies, transcendent experiences, and extraordinary minds."
The moral considerations of biotechnology are fascinating - hence the genre of books and movies toying with the concept. But sci-fi often becomes reality over time - far less time than we sometimes imagine. While most biomedical treatments are still therapeutic, some enhancements are already among us: vaccines, for example, do not remedy existing illness but empower the body to resist the onset of diseases to which humans are naturally susceptible. Supply and demand will ultimately dictate that women (or petri dishes, as the case may be) are treated with an embryonic wash to ensure the newly-conceived cell-cluster / baby is afforded an equal chance in the world (i.e., increased mental and physical attributes). Couple this with biotechnology to improve the senses and, eventually, mental capacity, and Superman will begin looking a bit more average (minus the flying bit, of course).
The question is whether there will come a time when we will simply cease to be human, as the term is presently understood - and whether there is a moral quality to the decision to effectively end the human race.