Leading article: Conservation comes in many forms

Conservationists tend to be a conservative lot, so it is hardly a surprise to learn that some zoologists dedicated to the preservation of animal species get prickly about the idea of using cloning and other reproductive technology to save their beloved wildlife. Quite naturally, and logically, they argue that it is nonsense to devote time and effort to preserving a species in a test tube if its habitat is being ruthlessly trashed in a way that makes life impossible in the wild. They would also point out that cloning is, by its very nature, the antithesis of sexual reproduction, which is nature's way of creating the wondrous genetic diversity that comes from mixing genes between males and females. Cloning, they would argue, does little to stop the relentless drainage of the world's dwindling gene pool.

Many scientists, however, disagree with this interpretation. They believe that the rate of species extinction around the world is now becoming so severe, and proceeding so fast, that every scientific tool available must now be employed to conserve the planet's wildlife and its genetic resources. Of course, the absolute priority should be to conserve natural habitats. But it is clear that this approach is failing in many parts of the world.

The jungle habitat of the northern white rhino in the Congo, for instance, is being ravaged by conflict, and the species has almost certainly become extinct in the wild, with the help of high-powered rifles. The few remaining northern white rhinos held in zoos have now been returned to a captive-breeding refuge in southern Africa, after breeding failures in zoos elsewhere. It makes sense to exploit what we know about mammalian reproduction, and the new techniques of induced pluripotent (iPS) stem cells, to see whether it is possible to build up a new breeding population using its far more numerous cousin, the southern white rhino, as a kind of surrogate mother.

This type of approach should not distract us from the main goal of restoring, or at least preserving, the wild habitats where endangered species live. That, of course, remains a priority. Equally, though, it is no longer viable for animal conservationists to dismiss scientific advances in reproductive technology as irrelevant to the task in hand. The simple fact is that we are currently living through the world's sixth mass extinction, this time due largely to human activity. The least we can do is not dismiss anything, however small or seemingly irrelevant, that may avert the tragedy that is unfolding before our eyes.