A common worry about the genetic engineering of human beings is that it will reduce human genetic diversity, creating a biological monoculture that could not only increase our susceptibility to disease but also hasten the extinction of our species. Thus far, however, the evolutionary implications of human genetic modification remain largely unexplored. In this paper, I consider whether the widespread use of genetic engineering technology is likely to narrow the present range of genetic variation, and if so, whether this would (...) in fact lead to the evolutionary harms that some authors envision. By examining the nature of biological variation and its relation to population immunity and evolvability, I show that not only will genetic engineering have a negligible impact on human genetic diversity, but also that it will be more likely to ensure rather than undermine the health and longevity of the human species. (shrink)

Human reproductive cloning provides the possibility of genetically related children for persons for whom present technologies are ineffective. I argue that the desire for genetically related children is not, by itself, a sufficient reason to engage in human reproductive cloning. I show this by arguing that the value underlying the desire for genetically related children implies a tension between the parent and the future child. This tension stems from an instance of a deprivation and violates a general principle of reasons (...) for deprivation. Alternative considerations, such as a right to procreative autonomy, do not appear helpful in making the case for human reproductive cloning merely on the basis of the desire for genetically related children. (shrink)