Its small size is a result of island dwarfing , a kind of allopatric speciation .
The Island Fox shares the Urocyon genus with the mainland Gray Fox , the fox from which it is descended .
Island Fox 's small size is a result of island dwarfing , a kind of allopatric speciation .
The Island Fox shares the Urocyon genus with the mainland Gray Fox , the fox from which it is descended .