History of the domestic sheep exact line of descent between domestic sheep and their wild ancestors is unclear. The most common hypothesis states that "Ovis aries" is descended from the Asiatic ("O. orientalis") species of mouflon. A few breeds of sheep, such as the Castlemilk Moorit from Scotland, were formed through crossbreeding with wild European mouflon. The urial ("O. vignei") was once thought to have been a forebear of domestic sheep, as they occasionally interbreed with mouflon in the Iranian part of their range. However, the urial, argali ("O. ammon"), and snow sheep ("O. nivicola") have a different number of chromosomes than other Ovis species,
Wild rice only travel about 30 inches away from a parent plant. If pollen does not land on a receptive female flower within that distance, no seeds are produced. Manchurian wild rice has almost disappeared from the wild in its native range, but has been accidentally introduced into the wild in New Zealand and is considered an invasive species there. The species most commonly harvested as grain are the annual species: "Zizania palustris" and "Zizania aquatica." The former, though now domesticated and grown commercially, is still often gathered from lakes in the traditional manner, especially by indigenous peoples in North America; the