National Geographic : 2011 Jul
historic fruit and vegetable varieties have van- ished. Of the , apple varieties that were grown in the s, fewer than a hundred re- main. In the Philippines thousands of varieties of rice once thrived; now only up to a hundred are grown there. In China percent of the wheat varieties cultivated just a century ago have disap- peared. Experts estimate that we have lost more than half of the world's food varieties over the past century. As for the , known livestock breeds, , are endangered or already extinct. Why is this a problem? Because if disease or future climate change decimates one of the hand- ful of plants and animals we've come to depend on to feed our growing planet, we might des- perately need one of those varieties we've let go extinct. e precipitous loss of the world's wheat diversity is a particular cause for concern. One of wheat's oldest adversaries, Puccinia graminis, a fungus known as stem rust, is spreading across the globe. e pestilence's current incarnation is a virulent and fast-mutating strain dubbed Ug99 because it was rst identi ed in Uganda in . It then spread to Kenya, Ethiopia, Sudan, and Yemen. By it had jumped the Persian Gulf into Iran. Scientists predict that Ug99 will soon make its way into the breadbaskets of India and Pakistan, then in ltrate Russia, China, and---with a mere hitch of a spore on an airplane passenger's shoe---our hemisphere as well. Roughly 90 percent of the world's wheat is defenseless against Ug99. Were the fungus to come to the U.S., an estimated one billion dol- lars' worth of wheat would be at risk. Scientists project that in Asia and Africa alone the portion of wheat in imminent danger would leave one billion people without their primary food source. A signi cant humanitarian crisis is inevitable, according to Rick Ward of the Durable Rust Re- sistance in Wheat project at Cornell University. e world's population is expected to reach seven billion people this year. By it could grow to nine billion. Some experts say we'll need to double our food production to keep up with demand as emerging economies consume more meat and dairy. Given the added challenges posed by climate change and constantly mutating dis- eases like Ug99, it is becoming ever more urgent to nd ways to increase food yield without ex- acerbating the genetic anemia coursing through industrialized agriculture's ostensible abundance. e world has become increasingly dependent upon technology-driven, one-size- ts-all solu- tions to its problems. Yet the best hope for se- curing food's future may depend on our ability to preserve the locally cultivated foods of the past. IT TOOK MORE THAN 10,000 YEARS of domestica- tion for humans to create the vast biodiversity in our food supply that we're now watching ebb away. Selectively breeding a wild plant or ani- mal species for certain desirable traits began as a tful process of trial and error motivated by that age-old imperative: hunger. Wild wheat, for example, drops its ripened kernels to the ground, or shatters, so that the plant can reseed itself. Early farmers selected out wheat that, due to a random genetic mutation, didn't shatter and was thus ideal for harvesting. Farmers and breeders painstakingly developed livestock breeds and food crops well suited to the peculiarities of their local climate and en- vironment. Each domesticated seed or breed was an answer to some very speci c problem--- such as drought or disease---in a very speci c place. e North American Gulf Coast Native sheep, for example, thrives in high heat and humidity and has broad parasite resistance. On the remote Orkney Islands, North Ronaldsay sheep can live on nothing but seaweed. Zebu cattle are more resistant to ticks than other cattle. In Ethiopia a small, humpless, short- horned cattle breed called the Sheko is a good milk producer that withstands harsh condi- tions and has resistance to sleeping sickness. Such adaptive traits are invaluable not only to local farmers but also to commercial breeders elsewhere in the world. Finnsheep, for example, long raised only by a small group of Finnish • Charles Siebert is the author of e Wauchula Woods Accord: Toward a New Understanding of Animals. Jim Richardson documented the importance of soil to our food supply in the September 2008 issue.