The survivor and the future

John Cornwell

THE SIXTH EXTINCTION: BIODIVERSITY AND ITS SURVIVAL by Richard Leakey and Roger Lewin Weidenfeld, £18.99, pp. 288 One of the great themes that loom over most religions, and pre-eminently Christianity, is eschatology: the approach- ing 'End Time'. And since a literal reading of the Book of Revelation suggests a link between millennia and the impending apocalypses, it is hardly surprising that there is more than a hint of dissolution in the air.

From giant asteroids to superbugs, there is no lack of fire and plague about to be unleashed on our heads in the current bout of dire expectations. For Richard Leakey and Roger Lewin, however, the coming doom is not so much a catastrophe from without, as the enemy within: the consequence of our own greed and lack of reverence for nature.

In a passionate and elegiac meditation, drawing deeply on Leakey's childhood in wild and remote places in Africa, the authors seek to persuade us that if we could alter our attitude towards nature, we might just stave off an impending mass extinction of species that would probably do for us too.

The 'Sixth Extinction', according to our authors, will begin with the disappearance of half the world's species during the next century. Unlike the five previous extinc- tions in the world's 530 million years (the fifth saw the end of the dinosaurs), this will be caused by us. And by the same token it could be averted by us. The problem, say Leakey and Lewin, is that we simply don't know how much trio- diversity, or richness of species, is required to sustain life on earth:

Through continued destruction of biodiversi- ty in the wake of economic development we could push the natural world over a thresh- old beyond which it might be unable to sus- tain, first itself and, ultimately, us.

This kind of ecological doomsaying is a familiar enough genre, but what makes these authors different from the main- stream is the scope of their definition of disaster and what they recommend to avert it.

The impending doom, they say, is not just a question of the destruction of our material sustenance: we have to contem- plate how nature 'succours the human psy- che in . . . some ineffable ways'. In other words, if we go on the way we are, life won't be worth living any way.

Humans evolved within a world of nature, and an appreciation, and need for, nature, are real and ineradicable components of the human psyche. We risk eroding the human soul if we allow the erosion of the richness of the world of nature around us.

The appeal is not merely to some pastoral, Wordsworthian notion of the beneficience of the countryside, but to a scientifically informed conservationism, in which Leakey's knowledge of palaeontolo- gy is matched by his and Lewin's familiarity with ecology and evolutionary biology.

And yet, powerful feeling is not entirely absent. Citing E. 0. Wilson, the authors, would have us emulate the emotion they call `biophilia', meaning emotional respons- es that touch the essence of humanity, the very essence of our history, in response to nature.

Yet there were times when they had me wondering. Is it really the case that most people 'secure a home in the countryside if they have the means to do so'? Most of my friends seem to be abandoning their coun- try retreats and week-ending by preference in town. And is it true that given 'visual choices among rural scenes,' people show an overwhelming preference for 'rolling landscape vegetated with scattered trees, preferably flat-topped trees'? Personally, I prefer mountains and the sea.

The authors are on more secure ground though when they declare that nurtured as we are in our artificial urban environments we do not see the relationship between the inputs and outputs of the natural economy of the Earth.

But The Sixth Extinction is at its best when the voice of Leakey comes through, telling us of his childhood in Africa, out in the wild, trapping dangerous animals, lead- ing a life of adventure, and how the 'daily horrors of seeing the spoils of poaching the elephant' brought him close to 'a deep, visceral passion for nature'.

It was these early influences, Leakey tells us, that gave him a taste of 'the hunter- gatherer way of life', which he believes must underpin the regard for nature that could save us from the next extinction:

Whether negative or positive, our response to wild nature, according to the biophilia hypothesis, is an ineradicable part of human nature. It is the heritage of aeons spent as hunter-gatherers in ancestral times.

Alas, it sounds a vain hope in this era of headlong urbanisation and politically cor- rect sensibilities about blood sports, that the populations of industrialised countries will ever retrieve a sense of Leakey's 'deep, visceral passion for nature' on this basis.

But then, for all its celebration of bio- philia, there is a seam of deep pessimism running through this book. In the final analysis Leakey and Lewin appear con- vinced that we will do too little too late.

And so, what makes the next extinction tragic, as it is virtually inevitable, in their view, is our knowledge of 'a solid explana- tion' for its cause. For each of the Big Five past extinctions there are theories of what caused them, none of them proven. 'For the sixth extinction,' say the authors, 'we do know the culprit. We are.'