Long before Darwin and Wallace, farmers and breeders were using the idea of selection to cause major changes in the features of their plants and animals over the course of decades. Farmers and breeders allowed only the plants and animals with desirable characteristics to reproduce, causing the evolution of farm stock. This process is called artificial selection because people (instead of nature) select which organisms get to reproduce. (info from UC Berkeley)
This pic shows that farmers have cultivated numerous popular crops from the wild mustard, by artificially selecting for certain attributes.
