A more secular philosophical concern about essentialism is tied to longstanding debates in philosophy of biology about species (see Erefshefsky 1992). Gilbert (1992) foresaw from the HGP a DNA-based definition of Homo sapiens: “At the end of the genome project, we will want to be able to identify all the genes that make up a human being. For example, we will compare the sequences of the human and the mouse and be able to determine the genes that define a mammal by this comparison…. So by compari