The simplest answer – and I hope I won’t be quote-mined on this – is that we can’t. Biology is messy, and unpredictable, and there’s the glib old Jurassic Park line that ‘life will find a way’. And there’s a lot of truth in that. If you talk about genetic engineering to a microbiologist, they sort of laugh to themselves, because the amount of things that bacteria can do that we keep discovering continues to surprise us.
Having said all of that, the types of modifications that are of useful interest to us at this stage tend to be much more straightforward, much finer-tuned modifications. It’s difficult to imagine how they could have grotesque repercussions.
"Every banana you eat is genetically modified – naturally occuring bananas are made up of indigestible seeds and are about the size of your thumb."
When it comes to crops, the question is always: how do we know that genetically engineered crops are not going to spread and enter the general eco-system? And we don’t. Crops do that. They’ve been doing that for ten thousand years. So the experiment becomes: does that increase or decrease bio-diversity? And the results are equivocal. Some experiments in the field say that they do, some say that they don’t. But every time you eat a nectarine, you’re eating a genetically modified food. Every banana you eat is genetically modified – naturally occuring bananas are made up of indigestible seeds and are about the size of your thumb.
The phrase we use is ‘prudent vigilance’. These are serious issues, so we do experiments cautiously, and carefully, and minimise the risks at every stage, and learn from past errors – like introducing rabbits to Australia, and all animals to New Zealand, and all the terrible fuck-ups from history when people have been too gung-ho. Cautious optimism, is how we progress.
I’m going to divert the question slightly, and do something I’m not meant to do, which is politicise the question. I don’t think the science is where the high risk is. The really significant risk in genetic engineering is in the ownership of things like crops and medicines. If we’re talking about a world, and I don’t think it’s unrealistic, where genetically modified crops are going to be a significant supply of food, particularly in poorer countries, then monopolised ownership of those seeds is a big deal, and something we need to think very carefully about. The question is how this technology can be deployed in a wide, safe and beneficial way.
"There’s that 20-year-old technology of getting spider silk into the genes of goats, so you can milk the goats and produce spider silk. We call them spider-goats, but they’re not. They’re goats."
We’re so influenced by science fiction. Most genetic engineering occurs in single cells, with very minor modifications to existing biochemical pathways, just to enhance one particular trait. There’s that 20-year-old technology of getting spider silk into the genes of goats, so you can milk the goats and produce spider silk. We call them spider-goats, but they’re not. They’re goats. They don’t look like spiders, they do behave like goats, everything they do is basically goat-like. They just also produce spider silk.
Hybrid animals of the type that might appear in 1950s B-movies. . . we can’t really do that. Biology is too messy and too complicated for us to be able to do grand-scale mad scientist things. Fun though it would be.