besides being a source of medicine biodiversity is also important for agriculture. Many varieties of food are already being lost. in the past 40 years,95 percent of the native wheat varieties in greece have disappeared. Today's modern agriculture depends on a dangerously narrow variety of species. Roughly 92 percent of the world's rice is grown in asia but only a few species. A disease or insect that affects one of these rice species could have a terrible impact on world food security . the irish potato were grown in ireland and all of these caught the same disease. Diversity reduces these risks. It also provides agricultural scientists with the material for breeding stronger species. Cross-breeding domestic plants with wild ones can improve yields and produce new types that are stronger against diseases and insects.
as for diet and health , throughout history it is estimated that human beings have used more than 10000 edible plant species,but now barely 150 are grown for the human diet. most people live off no more than 12 species. Doctors recommend a much wider variety of food for good health