“Of course it does. But hold it in your head for the moment. Because you’ve got another problem with your tomatoes. They ripen too fast. By the time you’ve picked them, packed them and shipped them to the shops they’re starting to go rotten. So along comes the genetic engineer, by now your very close friend, and says he has identified the gene in the DNA of your tomato that makes it shrivel and rot. He tells you he can remove the gene, modify it, and put it back in so that the tomato will ripen later on the vine and stay fresh for weeks, even months. Problem solved.”

Traffic had ground to a halt. Li leaned on the wheel and looked at her. “I thought you were trying to sell me the idea that genetic engineering was a bad thing.”

“Oh, I’m not saying that the idea in itself might not have some virtue. I’m saying that the current practice of it could be disastrous.”

“How?”

“Well, you think you’ve just created the perfect tomato. It is impervious to caterpillars, it’s got a long shelf-life in the shops, and you’ve saved a fortune on pesticides. But then the technology doesn’t come cheap. The company which employs the genetic engineer has spent millions on research and development, and they’re going to pass these costs on to you. And it’s not just a one-off cost, because the genetically engineered DNA is not passed on in the seeds. You have to buy them every year.

“Then you find that the poison that was innocuous to humans in the potato has combined with another substance in the tomato to create something that thousands of people have an allergic reaction to. Some of them die. And modifying that gene to slow down the ripening and rotting? It’s ruined the taste. So even if your customers don’t have an allergic reaction to your tomatoes, they don’t like the taste of them. You’re ruined.”

She grinned at the expression on his face. “But do you know what else? In moving these genes about, the geneticists used another gene that had nothing to do with either the potato or the tomato. They call it a ‘marker’ gene. All it does is allow them to check up quickly and easily on the results of moving the other genes about. But this gene was taken from a bacterium which just happened to be resistant to an antibiotic widely used in the treatment of killer diseases in humans. So what’s happening now? The people who eat your tomatoes, who don’t die of an allergic reaction, become resistant to certain types of antibiotic and start dying from diseases that have been under control for decades.”