Small but perfectly formed, South America's dart frogs are some of evolution's strangest by-products. They come in a vivid array of reds, oranges and greens and are so tiny they could perch on a fingernail.
Yet these little popinjays are the rainforest's most feared denizens, for each secretes poisons that can flatten even the largest predator. Take Colombia's wonderfully named Phyllobates horribilis. Each one has enough toxin to kill 10 men, a fact exploited by Choco tribesmen who rub their blow-gun darts (very carefully) over phyllobates when preparing for battle.
Then there is Equador's Epipedobates tricolor which exudes a cocktail of different chemicals, including one that medical researchers John Daly and Charles Myers discovered was a powerful, opium-like painkiller, but which seemed to lack addictive side effects.
And thereby hangs a tale. Having stumbled on this exceptional amphibian emission, Daly and Myers needed more samples to develop their research. So they returned to the little frogs' homeland glade, only to find it had been turned into a banana plantation. Thus a pharmacological miracle seemed to have perished forever at the hands of the fruit farmer. Only the subsequent discovery of a separate, distant epipedobates' lair saved the day.
Ecological horror stories are ten-a-penny, of course, and their capacity to alarm was long ago neutralised by overuse. This is 'the litany' that is disparaged by Danish statistician Bjorn Lomborg in his anti-green diatribe, The Sceptical Environmentalist, which so delighted right-wing commentators last year. For a few months, they nearly had us believing everything was tickety-boo on planet Earth.
The appearance of The Future of Life, is, therefore, timely, for it is not the work of desk-bound pedants who spend their days analysing and finding flaws in UN statistics but of the greatest natural history expert of our age, a double Pulitzer Prize winner, a distinguished Harvard professor and a renowned naturalist who has spent his life grubbing through the forest floor in search of novel wildlife.
And he can see absolutely no grounds for dismissing the warnings of the doom-mongers. 'An Armageddon is approaching,' he says. 'Not the cosmic war and fiery collapse of mankind foretold in scripture. It is the wreckage of the planet by an exuberantly plentiful and ingenious humanity.' We are back in eco-horror land, in other words, though never has it been so vividly and disturbingly described.
It is a majestic start from which Wilson proceeds lovingly to assemble a picture of the delicate interrelatedness of the 10 million species with which we share that biosphere - 'the Sumatran rhinoceros, flat-spined, three-toothed land snail, furbish lousewort' and all the other plants and animals that we are now eradicating at a stunning rate.
The trouble, Wilson says, is that human population growth has become 'more bacterial than primate', creating a biomass (the combined weight of all six billion humans alive today) that is now 100 times that of any other large animal that has ever existed. We already consume 40 per cent of Earth's green plants to feed our swelling numbers and will gorge ourselves on even more in the centuries ahead. The planet simply cannot take any more, no matter how much economists quibble over statistics, dispute extinction estimates and argue about agricultural production rates.
Only 'Palaeolithic obstinacy' stops us realising the danger, Wilson argues. We are descendants of Stone Age men and women who were hard-wired to commit themselves 'to a small piece of geography, a limited band of kinsmen, two or three generations into the future', and not much else. Hence we miss the global overview and end up as eco-deniers. The boys at the Economist must love being described this way.
In short, this is a brilliantly constructed analysis of our planetary woes, a much needed response to those who think our environments are safe and secure from global degradation. It is only when Wilson comes to solutions that he is on less sure ground. Some of his suggestions are eminently sensible - protect our last remaining great forests, cease all logging in ancient woodlands, increase our capacity to breed endangered species and support all population planning projects. These may well help to slow down the slaughter, but they will not stop it. His other proposals - calls to encourage biophilia (the love of living things) and urges to adopt a 'global land ethic' - will do absolutely nothing.
The trouble is that having outlined our global crisis so starkly, and having convincingly depicted life on a planet denuded of all variety or ecological interest, he clearly feels compelled to offer some salvation. Thus he states in the book's concluding sentence: 'A civilisation able to envision God and to embark on the colonisation of space will surely find the way to save the integrity of this planet and the magnificent life it harbours.' Compared to Wilson's opening sentence, these closing words are limp and inane and belied by everything else he has written. As he states earlier in the book: 'The conservation ethic, whether expressed as taboo, totemism or science, has generally come too late to save the most vulnerable of life forms. A paradise found is a paradise lost.' Not much room for hope there. In short, as a call to environmental arms, The Future of Life must be rated an honest failure. By contrast, as a swan song for our dying planet, it is a magnificent success.
Certainly we can see that the handiwork of millions of years of natural selection faces destruction in the twinkling of an evolutionary eye. Yet we have only just come to understand that process itself, one of the great intellectual triumphs of the past 150 years, and the basis of What Evolution Is, the first book that the godfather of modern biology, Ernst Mayr, has written for the public. Given that the venerated Harvard scientist is now 97 years old (and still carrying out research), this delay may seem tardy. It is a pleasure to say the wait was worth it, nevertheless.
'Evolution is a fact,' says Mayr. 'It has taken place ever since the origin of life', the end result being the improbable menagerie of life on Earth, from the ant to the doubting creationist, to whom Mayr pays special attention, mainly by demolishing all objections they can mount about natural selection's ability to explain the wonders of the living world. The only tragedy is that we now face losing most of those marvels in a single lifetime.