Along with the aboriginal inhabitants of Australia, they are believed to derive from the Proto-Australoids who emigrated from Africa between 50,000 and 100,000 years ago and dispersed along the southern edge of Asia, giving rise to Australoid populations in various places, including South India, Sri Lanka, the Andaman Islands, the Philippines, and others.The limit of this ancient migration was Sahul, the continent formed when Australia and New Guinea were united by a land bridge as a result of low sea levels. came into contact with these pre-existing populations of Papuan-speaking peoples.In the nineteenth century Robert Codrington, a British missionary, produced a series of monographs on "the Melanesians" based on his long-time residence in the region.In works including The Melanesian Languages (1885) and The Melanesians: Studies in Their Anthropology and Folk-lore (1891), Codrington defined Melanesia as including Vanuatu, the Solomon Islands, New Caledonia, and Fiji.) is a subregion of Oceania extending from New Guinea island in the southwestern Pacific Ocean to the Arafura Sea, and eastward to Fiji.The region includes the four independent countries of Vanuatu, the Solomon Islands, Fiji, and Papua New Guinea, as well as the French special collectivity of New Caledonia, and the Indonesian region of Western New Guinea.
Many apply the term only to the smaller islands, excluding New Guinea; Fiji has frequently been treated as an anomalous border region or even assigned wholly to Polynesia; and the people of the Torres Straits Islands are often simply classified as Australian aborigines.
He did not include the islands of New Guinea because only some of its people were Melanesians.
Like Bory de Saint-Vincent, he excluded Australia from Melanesia.
Most of the region is in the Southern Hemisphere, with a few small northwestern islands of Western New Guinea in the Northern Hemisphere.
The name Melanesia (in French Mélanésie) was first used by Jules Dumont d'Urville in 1832 to denote an ethnic and geographical grouping of islands whose inhabitants he thought were distinct from those of Micronesia and Polynesia.