Our amphibious individual has been endowed by its creators with sizeable portions of the human genome, the “best” qualities in the range of each trait or talent selected for. In addition, certain physical capabilities have been added which are outside of the human range of natural genetic possibility. Is this entity human? Amputees, paraplegics, and morons are all considered human, as are Olympic champions (though their gender may be in doubt), idiot savants, and geniuses; i.e., a human being is not defined by IQ or a physical description. So in the sense that “brain death” is death and mentally and physically handicapped individuals are nevertheless unquestionably human, so is our water-breathing friend a human being. But how much of the human genome can be replaced or augmented with genes outside the current population norms before we become uncertain in our identification of what is human and what is not? This is a crucial consideration in itself, but also leads to the question of the effect of human genetic changes on the nature of humanity as a whole.
In this larger sense, any permanent alteration of the human genome, whether within the human range or augmented outside of it, alters the nature of humanity by altering the distribution of potential traits within the population. Such genetic changes could also alter the nature of human interactions in ways that we cannot currently imagine. E.g., the increase in longevity we can expect right now on the basis of medical progress has already altered our society in significant ways: attitudes toward work, the role of government, social values (including increased separation between the generations), marriage and divorce, medical practice, the self-image of older individuals, and innumerable other aspects of our culture. What changes might be expected if the life-span were doubled or tripled? How would this affect the decision of when and whether to have children, for example, and/ or how they are raised?
Extending this example of an increase in life-span to include other changes in human characteristics (both physical and intellectual), the social and biological implications are enormous. It might well be valuable to extend our life-spans, eliminate near-sightedness, and replace all the “bad” genes, but is it equally valuable to select specifically for certain types of mental skills that we currently class as intelligence? What will we gain from that and, even more important, what might we lose? What is our ideal of a human being? And how much of that ideal, if any, transcends evanescent cultural values? What does being human mean? In summary, any significant genetic change in sizeable numbers of humans will be inextricably linked to changes in the nature of humanity itself: physically, mentally, emotionally, and culturally. Before we begin to significantly alter the human potential, serious thought MUST be given questions relating to what a human being is and what humanity is (and might become)