Enligt Wookieepedia , som i sig citerar Fullständig Star Wars Encyclopedia , evolutionen finns i Star Wars universum:
In the The Complete Star Wars Encyclopedia, gizka are referred to as a "fish" which was prized by the Selkath of Manaan rather than a reptilian species. The species, according to the encyclopedia, is said to have possibly evolved from a more rabid native on Lehon about four millennia prior to the Galactic Civil War.