The wild ancestor of Avena sativa and the closely related minor
crop, A. byzantina, is the hexaploid wild oat A. sterilis. Genetic
evidence shows the ancestral forms of A. sterilis grew in the
Fertile Crescent of the Near East. Domesticated oats appear
relatively late, and far from the Near East, in Bronze Age Europe.
Oats, like rye, are usually considered a secondary crop, i.e.,
derived from a weed of the primary cereal domesticates wheat and
barley. As these cereals spread westwards into cooler, wetter
areas, this may have favoured the oat weed component, leading to
its eventual domestication.