What if genetic engineering could be used to eliminate malaria once and for all?
Scientists are getting close to finalizing a technique called “gene drive” that could eliminate the species of mosquito that carries malaria. If put into place, it could help save the half-a-million people (most of whom are children) who die of malaria every year. But there might be some downsides.
Hi everyone, this is Jeff and welcome to Plain English, episode number 91 for Thursday, October 4, 2018. I’m back in the United States and had a really nice time in Mexico last week. JR and I had the pleasure of meeting a few listeners for coffee and snacks in Polanco, a neighborhood in Mexico City. We met with Iliana, Guadalupe, Mario, and Mario’s mom. We were able to chat for a couple hours. We talked about learning English in Mexico, learning Spanish in the United States, Mario’s also learning French, and our travels and differences between Mexican and American culture. It was a great time and big thanks to JR for organizing everything.
Today’s episode transcript can be found at PlainEnglish.com/91, where you’ll find translations of key words and phrases into Spanish, Portuguese, Japanese, Italian, Chinese and French. And to get episode summaries with additional vocabulary words and links to English articles, just head to PlainEnglish.com/mail and sign up there.
Genetic engineering to eliminate malaria?
Malaria kills about half a million people per year, mostly in Africa, and scientists might have found a way to completely kill off the mosquitos that transmit the deadly disease. The technology is called “gene drive” and it’s a form of genetic engineering. In genetic engineering, scientists alter an organism’s genetic composition, hoping to produce or eliminate specific traits future generations. Genetic engineering has been around for years, and is mostly used to make food more resilient—for example, to make tomatoes grow bigger and last longer, or for salmon to get bigger.
But in a technique called “gene drive,” scientists think they have discovered a way to completely eliminate a species of mosquito. They would do this by adversely affecting the way new mosquitoes develop. When this gene modification is introduced into the population, baby mosquitoes would not develop into either male or female, but would actually have physical characteristics of both. A mosquito that develops in this way can neither lay eggs (meaning it cannot reproduce) nor bite (meaning, it can’t infect humans). In a laboratory setting, researchers were able to completely eliminate a population of mosquitoes in 11 generations, which is fairly quick for mosquitoes. As far back as the 1960s, biologists conceptually outlined how they thought such mosquitos could be eliminated, but it is only now becoming practical to do so.
The actual human effects of malaria are tough to estimate, but in 2015 it is believed to have killed between 400,000 and 700,000 people, the vast majority of whom were under five years old. Ninety percent were in sub-Saharan Africa. Hundreds of millions of people—actually about three percent of the world’s population—suffers from malaria each year, and though they recover, they can suffer fever, chills, muscle pains, and general feeling of sickness to the stomach. Occasionally the symptoms are worse than that.
Malaria was once a big problem all around the world; it was common in France and the United States and other developed countries. The US eliminated malaria in the late 1940s and early 1950s with a national initiative that included draining mosquito breeding grounds, spraying houses with insecticide, and often spraying from airplanes. Today it is common in Africa and Asia.
It’s definitely a good thing we don’t have malaria here in the US, but I’m not sure that, given what we now know, spraying huge parts of the world from airplanes is a good idea either. Gene drives, however, present the opportunity to eliminate malaria without having to spray chemicals all over the place.
The story, though, is not that simple. It comes, as does so much these days with new technology, with ethical dilemmas. Do we really want to scientifically eliminate a species? How should that be done? And what might be the future consequences of employing this technology?
Let’s start with the first question: do we want to scientifically eliminate a species? It’s one thing to do it in the laboratory, but it is quite another to do it in the wild. Would this gene drive affect other species of mosquitos, potentially leading to a much bigger chain reaction than what was intended? Though mosquitoes are bad for humans, they are part of a complex food chain. What organisms farther up the food chain might be affected, and how will a whole ecosystem potentially change from losing just one small member? These are things that are difficult, if not impossible, to plan for.
Secondly, even if we can all agree that genetically modifying this mosquito is a good idea, you can certainly imagine that this type of technology might be used recklessly in the future—by scientists who are either not careful or worse. And national borders are just lines on the map; they don’t apply to ecosystems. The world doesn’t have a way to govern the use of these tools: so who controls what gene drives will be put into place?
These are tough questions, but they also have to be set against the real possibility of improving human lives. Scientists acknowledge the general worries about the potential abuse of gene drives, but they also believe that gene drives are a slow and methodical tool, and can easily be reversed. It is right to be cautious when thinking about making changes to our ecosystem, but it is also possible to be too cautious. If half a million people—the population of a medium-sized city—die every year, then there is a real human cost to delaying and contemplating the potential downsides. More than a thousand people die of this disease every day.
It seems right now, at least to me, that the world is treating this right. The scientists making the discoveries are being careful about the implications of their work and are working with the populations and the countries that are being affected. They are also working quickly to advance the new techniques so they can be used as soon as they are ready to be safely used.
A couple of listeners wrote to me this week and I wanted to make sure to say hi to them. Klinta from Latvia wrote, and she said she was positive she was the only Plain English listener in her country. So I went back into the stats and found that she’s not the only listener; it’s not possible to say how many people listen in a country, exactly, but you can see how many downloads the program gets over time and there are a couple hundred downloads from tiny Latvia. So Klinta, you have company out there in your country, and continue to spread the word for us.
Nick from Italy just started listening to podcasts and listens to business and photography podcasts as well as to Plain English, which is great. In fact, that’s one of the things we talked about in Mexico—the fact that even though you’re learning, you don’t want to just listen to a textbook in your ears, you want it to be something interesting. So I’m glad to hear Nick and so many others of you are listening to things of general interest to you. It makes English a little more fun.
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