Some researchers believe that the Chumash may have been visited by Polynesians between AD 400 and 800, nearly 1,000 years before Christopher Columbus reached the Americas. The Chumash advanced sewn-plank canoe design, used throughout the Polynesian Islands but unknown in North America except by those two tribes, is cited as the chief evidence for contact. Comparative linguistics may provide evidence as the Chumash word for "sewn-plank canoe", "tomolo'o", may have been derived from "kumula'au", the Polynesian word for the redwood logs used in that construction. However, the language comparison is generally considered tentative. Furthermore, the development of the Chumash plank canoe is fairly well represented in the archaeological record and spans several centuries. The concept is rejected by most archaeologists who work with the Chumash culture, and there is no evidence of a genetic legacy.