One popular response to the enthusiasm of the trans-humanists is to draw a line against interventions that might take their recipients out of our biological species altogether. This is usually framed as a minimal proposal to ban the clearest possible cases of immoral manipulation, on which everyone could agree. From proponents of “responsible genetics” (Council for Responsible Genetics 1993) to defenders of our “genetic patrimony” as the “common heritage of all humanity” (Knoppers 1991), to the “anti-post-humanist” life cycle traditionalists, the prospect of “species altering experiments” which might “direct” human evolution is provoking resistance (Mehlman, 2012).