Humans today rely upon just 20 varieties of plants for 90 percent of their
food. Experts throughout the world think that this lack of biodiversity could lead to an
agricultural calamity. The Irish potato famine, which led to the death or
displacement of two and a half million people in the 1840s, is an example of
what can happen when farmers rely on only a few plant species as the cornerstone of their crops.

Know your seeds! In just the last 15 years, more than half of the varieties
once available have disappeared from seed catalogs. By contrast, Seeds of
Change, an alternative seed company, grows over 2,000 kinds of seeds—a
hundredfold increase in the number of edible plants available to most people
today. The seed-preserving work of backyard gardeners and companies like Seeds of Change, total seed species and their
varieties will disappear forever.