Scientists have believed for some time that H.I.V.-1, the AIDS virus that has infected 30 million humans worldwide, originated in a primate species somewhere in Africa. Now a team of researchers led by Dr. Beatrice Hahn from the University of Alabama has confirmed that the source of H.I.V.-1 is almost certainly a subspecies of chimpanzee called Pan troglodytes troglodytes. This central African subspecies carries a simian version of H.I.V.-1, which was probably transmitted to humans who butchered hunted chimpanzees or handled their meat. Chimpanzees carry the simian version, called S.I.V.cpz, without falling ill. It may be possible to discover in their adaptation to this virus a means of blocking the further spread of H.I.V.-1.
The story of this discovery has a corollary. Pan troglodytes troglodytes is still being hunted, and with a rapacity that will guarantee its extinction before long. Chimpanzee meat, gathered by commercial hunters, feeds loggers in central Africa and even makes its way into urban restaurants. The issue is not just the danger of further cross-species transmission of the retrovirus, tragic as that would be. It is the destruction of a vital genetic reservoir -- the potential source of major innovations in AIDS research -- before research can really get under way. Before the significance of this new discovery can be assessed, it has to be studied among populations of free-living chimpanzees belonging to this subspecies. That will not be possible if they have been hunted to extinction.
There could be no clearer demonstration of the immediate human value of preserving biodiversity. The health of our species depends directly on the breadth of the global genetic pool to which we belong. The cure for disease, as scientists have often demonstrated, can come from the same source as the disease itself. But as always, recognizing the human value of biodiversity -- the utility of these chimpanzees to us -- carries with it a sense of profound sadness, an awareness of how hard it is to value biodiversity for itself. There is still a chance to save these animals, and with luck this new discovery will make their survival more likely.