During these same centuries, Polynesian navigators were carrying their high barbarism far across the Pacific. Their culture was at least loosely related to the cultures of southeast Asia. Ancestors of the Polynesians probably came from somewhere on the Asia mainland, but their great dispersion occurred only after the invention of outriggers permitted a canoe made from a single hollowed log to travel in safety across the open ocean. When this critical breakthrough had been made (about A.D. 600) Polynesians spread across the vastnesses of the Pacifiic within a few hundred years-afact attested by the close affinity of their languages in regions as distant from one another as New Zealand and Hewaii.