Changing the environment: Our unpredictable future

Changing the environment: Our unpredictable future.

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As a gardener, I appreciate the continuity of landscapes. I feel the bond that links our ancestors to a place and I see the reasons for what they did and marvel at how they did it with means far fewer than ours.

Human beings have altered the environment for countless generations. When we followed the great herds before we settled in our cities, we would have cleared patches of forest for temporary living quarters. Managing the landscape like this allowed grasses to grow and finally allowed them to be domesticated. With such a reliable food source, the scope was set for us to settle down and build our cities. Civilisation could begin.

Despite such a dramatic change, this progress was managed by nature through the constant of time. The domestication of horses, dogs, and cattle, was done through selective breeding to encourage those attributes that our ancestors deemed important. It was a gradual process, and one in which change was achieved at a natural pace.

But in the last fifteen years the world has changed. Our knowledge has led to designer crops and genetic tinkering that will alter parts of the environment far quicker than any selective breeding program. In short, rather than the stepping-stone of evolution, we are forcing organisms to make radical jumps to change the world in a way that we think is for the better. This pace of change is unknown in nature and lacks the maturing effect of time to ensure that it fits in with the ecology around it.

Don’t take me for a radical greenie who is opposed to any form of progress. I am not. We cannot hope to feed a growing world with current agricultural practices in the next fifty years. Our oil-based agriculture won’t last that long – the energy ratio for inputs vs outputs for modern agriculture is not sustainable. So we do need to think more radically.

Modern gene technology does hold some wonderful promises. This week it was announced that scientists have managed to create the much-sought after ‘anti-malarial mosquito.’ This insect is incapable of carrying the parasite that is responsible for malaria, and the idea is that they would breed with the wild mosquito population to spread the gene that prevents the parasite being carried. As insecticides and pesticides are losing their efficacy due to natural evolution in mosquitos, this is a viable new front in the war against malaria.

These scientists have even added a ‘marker’ gene so the insects can be visually identified: they have red eyes that set them apart from their natural cousins. Tests so far indicate that the parasitic resistant genes are passed onto 99.5% of second-generation mosquitos, which is a stunning success rate.

So far, the insects are still confined to laboratories, yet a prestigious group of scientists have cautioned that it might have: “unpredictable ecological consequences!”

I share their concerns. All of out domestication in the previous centuries and millennia has been gradual. It has evolved side-by-side with nature, and has found its place. What we are doing now represents a jump in this procedure, where time is no longer a safeguard.

To appreciate the rate of change, remember that that it took a decade to sequence the human genome back in 2003. Now, that much DNA can be sequenced in a single day.

Our ability to make radical changes to living organisms is growing to the extent that they are not able to fit in with existing ecosystems (or at the very least we can’t be certain how they will interact with them). Our appetite for change only grows as the promise of a better world beckons us on with ever-quickening strides.

And yet I am sobered by the words of a previous Astronomer Royal, Martin Rees, who once stated that there is a 50% chance humans could be extinct by the end of this century.

As our ability to change things grows, as our power does, and both in less time, it is ever more likely a mistake will be made.

Sometimes, in my darker moments, I think Rees might be an optimist.

You can see a video of Martin Rees’s speech and reasoning at a TED lecture here:

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