The video below is the fifth part in a six-part series examining the scourge of Ug99, a type of fungus that causes disease in wheat crops — one that scientists worry could threaten global food supplies. Visit our series archive for all published episodes.

Ethiopia is one of the oldest cultivating regions not only for wheat, but also for other crops like coffee, millet, and barley. Over thousands of years, the environment and farmers have interacted by selecting and breeding in order to adjust old crop varieties to regional conditions. The result is a unique variety of crop variations, and today, Ethiopia is recognized worldwide as a center for genetic diversity.

The Russian botanist Nikolai Vavilov identified these centers as early as 1926. He noticed that in Peru, for example, there were thousands of potato varieties, while South and Central America had many different tomatoes and Central Asia saw a wide variety of carrots.

In Ethiopia, the diversity is in wheat — durum wheat in particular.

Today, in order to combat Ug99 and other pathogens, breeders take advantage of those diverse genes. The old varieties are an important source for new genes, because genes can’t be produced from scratch. In a constantly changing world, where pathogens adapt and other environmental conditions keep changing, a diverse gene pool for breeders to draw from is often the best insurance for the future.

Coming Thursday, Part 6: Living With the Enemy

Kerstin Hoppenhaus and Sibylle Grunze are the founders of Hoppenhaus & Grunze Media, a Berlin-based film production studio specializing in documentary coverage of science.