The cultivation of various plants and their domestication first spread to the Fertile Crescent and then independently to other parts of the world, such as China, Mesoamerica (Mexico), South America (Ecuador, Peru), and the Mississippi Valley. Of the 200,000 wild plant species, only a few thousand are edible by humans or have been, and only a few hundred have been domesticated. Today (10,000 years after the invention of agriculture), only a dozen or so account for 80% of annual crops (by weight). These are: wheat, corn, rice, barley, sorghum, soybeans, potatoes, cassava, sweet potatoes, sugarcane, sugar beets, and bananas.
