The international reliance on large-scale factory farms has resulted in the loss of thousands of varieties of fruits, vegetables, and grains. Cary Fowler, who works for the United Nations brokering international agricultural genetic exchanges, was in Memphis earlier this month visiting family. We sat down to discuss the problem and what is being done about it.
Flyer: Explain the importance of genetic diversity.
Fowler: When most people think about biological diversity they think pandas and whales and things like that, but of course what keeps most species alive is the diversity within the species. People think species extinction is some event -- when the last individual dies. But in agricultural crops, and in everything else, we ought to think about extinction as a process rather than as an event. It's a process where a species loses the ability to evolve. And it loses the ability to evolve when there's not enough genetic diversity to facilitate that evolution. To some degree, you can say something is functionally extinct even if there are quite a few of them around. If all the dogs in the world were Pekinese, how reassuring would that be?
Because one disease can come along and wipe them all out?
Right. Many people find it hard to get emotional about carrots or tomatoes or wheat in the same sense they would about seals and sea turtles and things like that, but we ought to be thinking about the genetic diversity within our major agricultural crops if we want them to be around very long.
Are many varieties being lost?
Yes, there has been a tremendous decrease in species. I wrote a book called Shattering on this same issue. Frankly, there is very little good data on this. We never had a good head count in the first place, so we don't know what existed. We don't know how much was lost in terms of numbers of varieties.
Probably the best data is from the United States. Around the turn of the century the department of agriculture was surveying varieties of apple trees, pear trees, cherries, broccoli, cauliflower, wheat -- everything. If you check back now, about 85 percent of the apple trees that existed around the turn of the century are gone. Extinct. Never to be seen again. And, of course, the diversity, characteristic diseases, pest resistance, nutritional quality -- in a sense the history of that apple going back thousands of years -- is also gone. That's part of what I'm involved in doing: working to conserve that genetic diversity for the future.
There are now very large collections of seeds being kept in freezers. They're called gene banks, and the institutions I work with hold probably the widest selections of this genetic diversity in the world. We are actively breeding 24 crops, most of the major food crops in the world, and we have large collections of these materials -- 80,000, 90,000, 100,000 varieties. We have over 100,000 varieties of rice. Breeders use these varieties in breeding programs.
There has been a lot of effort in the last 25 years to conserve this material. This is the raw material of the future of agriculture; without this we would have mass starvation on a scale you couldn't imagine because we wouldn't be able to keep up with the environmental changes that agriculture has to adapt to. And funding is more or less year by year for something we have to have for the future.
When I first started working on this about 25 years ago, people's eyes would glaze over when you talked about genetic diversity. They didn't know what it meant. But if you asked them if tomatoes taste as good as they did when you were growing up, people would say no. Then one begins to understand there are different varieties.
Go to the Andes, the home of the potato, and cut open a potato. Some will be white like the ones we have here; some will be red, purple, black, yellow, a whole range of colors. You look at tomatoes, eggplants -- they come in a gigantic variety of colors and shapes.
And these varieties have different qualities for different climates?
Yes. It's easy to see the visual differences in beans or apples. What you don't see is that over the 10,000- to 15,000-year history of agriculture, they became adapted to different environments. So we have apples that are appropriate in warm climates or in the winters of Norway. That might not be something you can see when you look at a fruit, but they all have different adaptations to pests, climates, and diseases. There are apples that have eight times the vitamin C of the average orange. So when they say an apple a day keeps the doctor away, it really depends on what variety you choose.
So when I go to the store and pick up an apple, what is that variety bred for?
In a normal store at this time of year, you are eating last year's apple. So that apple is bred for cold storage, among other things. Some really nice apples won't take that -- delicious apples -- but not commercially viable on a large scale.
What's your take on the controversy concerning genetically modified crops?
We are working on drought-tolerant maize that's getting out in farmers' fields. This is going to save hundreds of thousands of lives and save a significant amount of environment in southern Africa because they won't be tearing up land to plant larger fields of corn. The corn doesn't use any alien gene -- it's found in another variety of corn -- but we use modern biotechnology techniques to get the proper trait for the poor southern African farmer. I don't have too many problems with that. But the risks go up when you start transferring genes from, say, fish to plants.
You can e-mail Andrew Wilkins at email@example.com.