Crop plants: Plants that are valuable for humans as food or for their industrial, aesthetic or other value. Some of them are cultivated crops (around 650-700 species), but most of the world's arable land is occupied by only a few species (wheat, rice, maize, barley, sorghum, etc.). Others are wild plants (e.g. herbs, wild fruits), valuable only if the workforce necessary to gather them in is available.
Livestock: All domesticated animals kept to provide people with food, protection or labour (e.g porterage, herding, tracking), or for profit. Initially man used for feeding and clothing what Nature offered to maintain their hunting, fishing, gathering lifestyle. After the ice age humans started to shape the environment to meet their needs: they determined the living conditions of domesticated animals. Domestication of animals started about 11 thousand years ago.