The UK government has just declared that synthetic biology – the science of making novel living organisms – could lead to a new industrial revolution and should be a research priority. Many environmentalists argue instead that creating new life forms could endanger the existing ones. But it may be that synthetic biology is our best hope of preserving life on our planet.
Mankind has, and continues to have, a huge impact on the planet. About 50,000 years ago, much of Australia was covered in dense rainforests grazed by large herbivores who were preyed upon by roaming marsupial carnivores. Ten thousand years later the forests, the megafauna and the carnivores were all gone. What happened? Many explanations have been proposed, such as climate change or ecosystem collapse, but a recent extensive study of pollen samples by Susan Rule and colleagues of the Australian National University points the finger at a single culprit: man. People arrived on the northern coastline about 45,000 years ago and burnt and hunted their way across the continent, leaving a trail of destruction and extinctions in their wake.
A similar wave of extinctions followed the peopling of the Americas about 15,000 years ago; and also accompanied the arrival of modern man into Europe, in that case taking with it our Neanderthal cousins. Everywhere we have travelled we have squashed thousands of species beneath our boots.
Almost always the harm is unintentional, a kind of byproduct of our own success as we clear land to grow crops or kill game to roast in our fires. Conventional technology has given us a bigger boot print that treads even the upper layers of the Earth’s atmosphere. This is only likely to get worse as populations expand and more people demand western lifestyles. The natural world’s coping capacity may be close to critical. The solution may be to expand the natural world.
Most of human expansion came through manipulating nature. When we ran out of game to hunt, we domesticated the wild auroch and turned it into a cow. When we ran out of seeds to collect, we cultivated wild grass and turned it into wheat, corn and rice. Each of these, and many other domesticated species, is as much a product of technology as the mobile phone or the car.
But the future holds greater challenges than the past. Feeding nearly 10 billion people by 2050 while fuelling their cars and clearing up their waste threatens to exhaust the planet’s handling capacity.
Synthetic biology may provide at least some of the answer. Scientists have already developed genetically modified crops that can provide higher yields from less land and more resistance to drought, disease and pests. But SB technology is to GM as a car designer is to a mechanic. Whereas a mechanic can improve the performance of an automobile, only a designer can make a Maserati 250F. No amount of tinkering will ever turn a Ford Cortina into a Ferrari.
Current GM crops are the Ford Cortinas of agriculture, but synthetic biologists aim to make Ferrari plants that perform photosynthesis more efficiently by harvesting light from wider regions of the spectrum, or even capture nitrogen directly from the air so they won’t need nitrogen fertiliser. New microbes are being designed that eat and degrade toxic pollutants or turn agricultural waste into electricity.
Of course there are dangers. But doing nothing is also dangerous. Unchecked population growth is likely to cause far more extinctions than any synthetic organism. The current generation of synthetic organisms is being built with genetic weaknesses that will disable them if they escape from the laboratory.
Of course, for uses such as clearing up an oil spill, SB organisms will need to get out of the laboratory so they must be designed to at least survive in the environment. So could released synthetic bugs kill us? The astronomer Fred Hoyle famously compared the chances of random forces generating a living organism as similar to that of a hurricane blowing through a junkyard assembling a Boeing 747. A synthetic biologist would argue that the chances of an engineered oil-eating microbe being able to cause disease in humans would be similar to the chances of a Boeing 747 flying to the moon. Pathogens and environmental microbes are very different beasts and extremely unlikely to succeed in each other’s territory.
Nothing is without risk but SB’s forerunner, GM, is probably the only technology that, as far as we know, has never caused significant harm (and yet has fed millions). SB technology has, so far, been extremely safe. Far from being a threat to the planet, synthetic biology may be our best hope for a healthy future.
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