This is a reminder that the most dangerous threat to the long-term survival of the human species is the human race itself. Of course, this has been obvious for some time. My generation and the one before us grew up with the fear of a nuclear holocaust. Even though the number of nuclear missiles has been reduced, the list of countries possessing this technology has grown, and with it the probability that one day somebody will push the button. My children’s generation has grown up with the threat of global warming, a process whose consequences could be as destructive, albeit much slower. The human race is not very quick to understand novel threats. Just a few years ago, the president of the United States refused to ratify the Kyoto protocol on the basis that the ‘American way of life is not negotiable’, as if the core of American civilisation and values were the four-wheel drive vehicles produced by three large corporations that barely survived the end of this president’s term in office.
In this context, the one new message that the HIV epidemic, as chronicled in this book, should bring home is that well-intentioned human interventions can have unpredictable and disastrous microbiologic consequences. Mankind has emerged through a process of natural selection over billions of years. Apart from ourselves, there is probably no other living organism on earth that could destroy us completely, because if such organisms had existed, we would not have managed to reach our current status in the first place. But as I write these lines, there is renewed interest in sending humans on a wonderful voyage to Mars and back. The kids who watched Neil Armstrong’s small steps on the moon are now engineers, pilots, administrators and politicians. They think that their own generation also needs to push back a new frontier, that this is part of the human experience, and perhaps something that will provide an answer to perennial questions about the meaning of life. For a long time I have thought that space adventures were very unwise. What is the point of setting up a small human colony somewhere in orbit around the earth or even further away, when we are systematically destroying, day in and day out, the only planet which can sustain human life? Would it not be smarter to spend our resources and ingenuity on scientific adventures whose purpose would be to protect our earth rather than taking the risk of importing into our cherished planet a completely different form of microscopic life, perhaps not even based on DNA, and whose innocuous nature has not been proven by billions of years of natural selection and co-evolution with us?