The unravelling of the full sequence of the human genome-a list, in order, of the chemical bases that encode the information needed to assemble and run a human body-is a scientific wonder. It is not diminished by the fact that what have been announced are "draft" sequences, and that dotting every genetic "i" and crossing every "t" will actually take years. Nor is it diminished by the fact that this particular race was not to the finishing-post, but to the starting line.