Having spent time contemplating the nature of personhood, the following comment, from a review by David Hull, made a certain amount of sense:
'A ... reason why so many people are so conservative with respect to species is that we human beings form a species. If something is true of all species, then it is true of our species, and lots of people do not want to visualize the human species as part of a genealogical network. According to the class interpretation, a certain list of characters defines Homo sapiens. Anyone who lacks one or more of these characters is either not a human being or not a normal human being. On the part-whole interpretation, a newborn baby born without plantigrade feet is still a human being. If your parents are human beings, then you are a human being. If you mate successfully with another human being, then you too are a human being. Homo sapiens, like all sexual species, is part of a particular genealogical nexus. That may not sound right, but there it is.'
It must be asked whether or not genealogy forms a viable basis for personhood? Do we want to be able to say that anybeing born of a human being is automatically a person? Conversely, do we want to say than anybeing not born of a human being is not to be accorded personhood?