Since the beginning of civilisation, humans have been domesticating wild plants such as wheat, barley and rice. They have both conciously and unconciously selected plant types suited to cropping.
Reccently, there has been an increasing effort to domesticate a greater variety of wild plants, especially legumes.
Buirchell, Bevan and Cowling, Wallace
"Domestication of rough-seeded lupins,"
Journal of the Department of Agriculture, Western Australia, Series 4: Vol. 33
, Article 2.
Available at: http://researchlibrary.agric.wa.gov.au/journal_agriculture4/vol33/iss4/2