The domestic fowl originates from the junglefowl, the four species of which are distributed in southern Asia from Pakistan to Indonesia. Stevens (1991) summarizes the situation as follows. The Red Junglefowl (Gallus gallus) has the widest distribution and is thought to be the main progenitor of the domestic fowl, though some genes have probably been introduced from other species by hybridization, particularly in Asiatic breeds. Those who favour a single or monophyletic origin refer to the domestic fowl as G. gallus, while those who believe in a multiple or polyphyletic origin call it Gallus domesticus or G. gallus domesticus, depending on whether it is regarded as a species or a subspecies.