Anthropologists have disagreed about the exact geographical boundaries of Melanesia, some using the term to designate only the islands east of New Guinea, though without arguing that New Guinea is culturally distinct. Others have suggested that Fiji, because of its links with Tonga, should be considered part of Polynesia. Here, following the most common usage, Melanesia will be understood to extend from New Guinea in the west to Fiji in the east, encompassing the islands of the Torres Straits, the Bismarck archipelago, the Solomons, Vanuatu (formerly the New Hebrides), New Caledonia, and many smaller islands.

Within the northeastern part of this region, a few islands are inhabited by people whose languages and cultures are classified as Polynesian, such as the inhabitants of Tikopia and Bellona. Although these peoples' homes now belong to the same political units as the Melanesian islands, scholars consider them part of Polynesia...