I had a conversation with a geneticist friend the other day, where we discussed the enormous potential danger of genetic technology. The problem, as I saw it, was that genetic engineering was likely to become a far greater threat to humanity's survival than thermonuclear weapons. Nukes have the advantage of being extremely technically complicated and difficult to assemble. Building such weapons requires thousands of people cooperating under the auspices of a nation state. But it is not difficult to imagine a near future where humans have genetically re-engineered much of their environment. This is already the case for much of the earth's surface. What will happen when genetic engineering becomes cheap, easy and widespread? Does anyone think that we, as a species, will be able to handle that kind of power responsibly? This scenario must give even the most blinkered techno-utopian optimist pause for thought.