The wild ancestor of "Avena sativa" and the similar minor crop, "A. byzantina", is the hexaploid wild oat "A. sterilis". Science of DNA shows that the ancestor forms of "A. sterilis" grew in the Fertile Crescent of the Near East. Domesticated oats appear later. They are also far from the Near East, in Bronze Age Europe. Oats are like rye. They are normally thought as a less important crop, i.e. coming from a weed out of the main cereals wheat and barley As these cereals spread into cooler, wetter places, this may have favored the oat weed. This quickly leads to its common use.