Fritz Allhoff has recently offered an extremely compelling challenge to the morality of human cloning. He argues that a biological phenomenon, that of telomere shortening, undermines the moral permissibility of human cloning. Telomere shortening is caused by cell replication, and appears to be one of the central reasons that cells and organisms age and die. Allhoff considers a thirty-year-old woman who wishes to create a genetic clone. He notes that the DNA from her cell that would be used to create (...) the clone would have shortened telomeres—as it would have gone through many generations of cell replication. As a result, the clone would begin its existence with shortened telomeres; the clone’s telomeres would be the same length as the woman’s telomeres at the time of cloning. The moral problem lies in the fact that because of shortened telomeres, the clone will senesce more rapidly as compared with noncloned organisms, and would have increased susceptibility to degenerative conditions and diseases. Allhoff then goes on to argue that earlier senescence and disease susceptibility constitute a moral ground for rejecting cloning because “the life of a clone would be worse than that of a non-clone”. This line of argument is rooted in Parfit’s The Same Number Quality Claim : “If in either of two outcomes the same number of people would ever live, it would be bad if those who live are worse off, or have a lower quality of life, than those who would have lived”. Applying Parfit’s Q principle to cases of cloning, it could be argued that parents ought to produce children that would be maximally well off, and since clones would be worse off than children produced “normally,” it follows that parents should avoid cloning. As Allhoff puts it, “obviously sexual reproduction would not transfer shortened telomeres to offspring so, all else being equal, sexual reproduction is better than cloning ”. For this sort of line to pack any moral punch, Q must be interpreted rather strongly. (shrink)