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A certain spider (Nephila clavipes) makes six different kinds of silk. When hit by a fast-flying moth it can stretch by 40% and then return to its original size unaffected. The US army is researching spiders because their web is stronger, and has better energy-absorbing elasticity, than Kevlar, a fibre so tough that it can stop bullets. Kevlar is made by pouring petroleum-derived molecules into a pressurised vat of concentrated sulphuric acid to be boiled at several hundred degrees Celsius and then subjected to high pressures. A spider just needs a fly or two. A hummingbird can fly forwards, backwards, up, down or sideways, with equal ease. It can fly across the Gulf of Mexico on three grams of fuel and, when picking up its fuel, fertilise the flower to provide more fuel in future. Compare the resources consumed and the damage done in building and flying a Chinook. We have a lot to learn. Architects are fascinated by the ability of termites to build structures that maintain a constant temperature in their interior chambers. Computer scientists think that ants might help them with parallel, rather than linear, computers. And if we want a lot of hydrogen, now that we are entering the hydrogen economy, nature makes it all the time with the help of an enzyme. Can we mimic nature? Material scientists boast about the incredibly high pressure they can achieve to make hard ceramics (an oyster beats them), high temperatures for special steels, and elaborate chemical processes (they can't match a mollusc for underwater glue). Theirs is outmoded Stone Age technology -- heat, beat and treat. Some agricultural researchers are noticing that nature does not use the plough. Plants naturally grow as mixed communities, with seldom fewer than four species together. Nature favours perennials. Even organic farming still has a lot to learn from nature. Then energy. Almost all our energy comes from the sun -- via plants. Coal and oil are embodied energy captured millions of years ago. Duckweed captures solar energy with 95% efficiency, many times better than man-made photovoltaic cells. A leaf takes in water and carbon dioxide, the carbon forms sugars that store the sun's energy, and oxygen is given off. But how? Scientists refer to `membrane potential' where a positive electron is moved to one side of a membrane and a negative electron to the other. If we could mimic that, and if the process needed no more inputs than stagnant water and daylight, and produced no more waste than duckweed produces, we would have a truly sustainable energy source. The scientific race is on. Genetic knowledge is the biggest recent leap forward, but experience suggests that immensely powerful new technologies should be approached with caution. Fossil fuels, while making possible the lifestyle we value, have been largely responsible for overpopulation, degraded land, changing climate, rising sea levels and resource wars. We are on a unique planet on which life has evolved in a unique way and we must live within the planet's unique patterns. In three billion years, all sorts of diverse properties have been combined, like crystals and membranes in a spider's web. But not everything. Boundaries have been erected, and it is these boundaries that we are excitedly destroying when taking genetic inheritance into our own hands. The most pressing need is to recognise how use can be made of genetic knowledge without upsetting three billion years of evolution. Novel genes may cause havoc as they move vertically and horizontally through future generations of bacteria, plants, animals, and ourselves. Biomimicry introduces an era based, not on what we can extract from nature, but on what we can learn from her. "Doing it nature's way" has the potential to change the way we educate our children, grow food, make materials, harness energy, heal ourselves, store information and conduct business.
Excerpted from The Little Earth Book by James Bruges, published by Alastair Sawday. To order a copy or for further details visit www.littleearth.co.uk
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