Oceania is a geographical region with disputed borders but generally encompasses Australia, New Guinea, Melanesia, Micronesia, and Polynesia.The division of Oceania into three historical regions is now being questioned by some researchers, who find it irrelevant and prefer the concepts of Near Oceania and Remote Oceania.
The prehistoric peopling of Oceania took place through two major expansion movements. The first occurred between 50,000 and 70,000 years ago and brought Homo sapiens hunter-gatherers from continental Asia to populate Insulindia, then nearby Oceania, i.e. New Guinea, Australia, and certain Melanesian islands.
The second wave is more recent, starting around 6,000 years ago. Farmers and navigators from Taiwan, speaking Austronesian languages, populated Insulinde, i.e. the Philippines, Malaysia, and Indonesia. From the eastern islands of Indonesia, these Austronesian navigators made their way, from 1500 BC onwards, to New Guinea and Melanesia, then to the islands of distant Oceania. They were the first to reach Micronesia and Polynesia. Tonga, in western Polynesia, was first settled around 3,300 years ago. Perhaps a millennium ago, they even reached South America. Finally, Austronesians speaking Barito languages, who may have started from Borneo further west, reached the African island of Madagascar 1,500 years ago, making it the fourth major Austronesian island in linguistic terms.
All along the way, the populations of the first and, above all, second waves of settlement mixed to a considerable extent, both culturally and genetically. Focusing on these two major waves of modern human settlement, this does not rule out intermediate colonization: the Pama-Nyungan wave in Australia from south of Sulawesi (Toalian culture), and the Trans-Neo-Guinean wave in New Guinea.
The question of the origin of the Oceanians has been one of the major themes of Oceanic research since the 19th century. Today, thanks to archaeology, linguistics, ethnolinguistics, ethnobotany, and genetics, there is a more or less coherent answer to this question, but many points remain unresolved.
The first Homo sapiens in Oceania
There is no known evidence of archaic human species having outgrown the Wallacea to establish themselves in the Sahul (Australia and New Guinea), before the arrival of the first Homo sapiens in Australia. Flores Man, present on the island of Flores in Indonesia since at least 700,000 years Before Present (AP), is not known outside Flores.
Genetic research has revealed partial hybridization between the first Homo sapiens to arrive in the region and Denisova Man, who probably populated much of eastern Asia before the arrival of modern humans. This research also shows a possible weak hybridization of East Asian Homo sapiens with another as yet unidentified local human species.
Around 70,000 years ago, insular Southeast Asia was not the archipelago it is today, but a continental shelf, the Sunda plateau, a peninsular extension of the Asian continent. Australia's shoreline extended much further into the Timor Sea. Australia and New Guinea, linked by a land bridge across the Arafura Sea, the Gulf of Carpentaria, and Torres Strait, formed a single landmass called Sahul, which also encompassed Tasmania. Between Sunda and Sahul lay an archipelago that geographers call Wallacea, the eastern part of Indonesia. At that time, it was possible to travel from Sunda to Sahul without having to cross more than 100 km of sea.
The Peopling of Sunda The first migrations of Homo sapiens to Sunda and Wallacea are poorly understood, and are thought to date back at least 60,000 years.
Today's Negrito populations testify to the fact that an ancient population layer, now marginalized and submerged by Austronesian farmers, settled in Sunda. It also spread further afield, as these populations, now relict, also live in the Andaman Islands and the Philippines. The Negritos are probably the oldest modern humans in Southeast Asia (along with the Ainus of Japan, the Hmong-Mien, and the ancient Qiang of Tibet), with the ancestors of these groups settling in the region at least 70,000 years ago.
Despite their similar appearance (very dark skin, frizzy hair, short stature), genetic analyses of the various Negrito groups show an uncertain kinship, which would indicate a very ancient settlement origin. Cross-breeding with neighboring Austronesian populations has also blurred the genetic signature of these populations.
The Peopling of Sahul
Migration from Sunda through the Wallacea occurred during the Late Pleistocene, when sea levels were much lower than today. Repeated episodes of glaciation during the Pleistocene resulted in sea levels 100 to 150 meters lower than today. Between 70,000 and 50,000 years ago, the first settlement occurred in the Sahul (New Guinea and Australia).In 2003, Ingman and Gyllesten used mitochondrial DNA analysis to estimate that Australia was settled between 40,000 and 70,000 years ago. See Ingman and Gyllesten, "Mitochondrial genome variation and evolutionary history of Australian and New Guinean aborigines", article published in Genome Research (13(7): 1600–6). Quoted in "The Australian Aboriginal People: Dating the Colonization of Australia", an article by Tressa Jamison published on Biology @ Iowa State, a site of Iowa State University.
A 2007 genetic analysis concluded that the "settlement of Australia and Papua New Guinea by modern humans was carried out by a single group of people who remained in substantial or total isolation until recent times. The finding would rule out hypotheses about later waves of migration [...]. The Aboriginal peoples of Australia and the inhabitants of Papua New Guinea would be the descendants of a single founding population". Genetically, these earliest human migrations into Sahul are associated with the divergence of the Ancient East Eurasians lineage. Other recent genetic evidence from Aboriginal Australians and Papuans also suggests that these peoples originated from a common ancestral population, eventually diverging in their respective genetic groups after an initial bottleneck, with little evidence of subsequent gene flow.
Humans are thought to have sailed between the Wallacea and the Sahul, then diffused across the continent. Models converge on the idea that the first entry into New Guinea via Sulawesi is the most likely, although a southern route through Bali, Timor, and onto the Sahul plateau now drowned in the Arafura Sea north of the modern Kimberley region of Western Australia is also plausible, the two hypotheses not being mutually exclusive. The Sahul settlement is now the oldest evidence of deep-sea navigation. A much earlier island settlement is known towards the island of Florès, but over a much shorter sea distance. To reach Florès, the widest strait (based on sea level at the time) was only 19 km, so it was always in visual contact with a coastline.
Archaeology has revealed a human settlement in the headwaters of the Swan River in Western Australia, dating back 38,000 years. According to excavations at the Warreen Cave site, humans arrived in Tasmania, then linked by a land bridge to Australia, around 35,000 years ago.
"At the same time, the few dozen kilometers separating the Bismarck Archipelago from Sahul were crossed: New Britain and New Ireland were reached, and then, one hundred and sixty kilometers away, the Buka Island in the north of the Solomon Archipelago: a true 28,000-year-old feat. Finally, to close the first phase in the settlement of Oceania, Manus Island (Admiralty Islands), 240 km north of the Bismarcks, was inhabited by Oceanians 12,000 years ago".
By this date (12,000 B.C.), the expansion of first-wave settlers seems to have ceased. The Solomon Islands, just south of Buka Island, remained untouched by human occupation. "In the present state of knowledge, there is a time gap of more than eight millennia before the race towards the ocean is resumed".
Between 6,000 and 12,000 years ago, with the end of the last Ice Age, sea levels rose to their present level, submerging the land bridges between Australia and New Guinea on the one hand, and Australia and Tasmania on the other.
The populations of New Guinea, Australia, and Tasmania are now developing separately. The ancestors of the Papuans of New Guinea, at least those from the highlands, developed a complex horticultural system. Its earliest traces date back 9,000 years, just after those found in Mesopotamia, which are generally considered to be the oldest. For example, "the ancient agricultural region of Kuk, in Papua New Guinea, comprises 116 hectares of marshland in the west of the island of New Guinea, at an altitude of 1,500 meters. Archaeological excavations have revealed that these marshes have been farmed almost continuously for 7,000 to 10,000 years. The site has well-preserved archaeological remains showing the technological evolution that transformed plant exploitation into agriculture".
In contrast, Aboriginal Australians remained hunter-gatherers, as geoclimatic conditions were less favorable to agriculture, with a highly irregular rainfall pattern.
The Austronesian wave
Asian origins
6,000 years ago (circa 4000 BC), millet-and rice-growing coastal dwellers from southern China began crossing the Strait to settle in Taiwan. Their descendants, still speaking Austronesian languages, are today's Taiwanese Indigenous peoples.
Around 2500 BC, migrations took place from Taiwan to the Philippines.
Between the end of the 3rd millennium and 1500 B.C., new migrations led to the settlement of groups that archaeology identifies as coming from the Philippines to northern Borneo, Sulawesi, and Timor, and from there to the other islands of the Indonesian archipelago. The cultivation of rice began to decline in some areas in favor of new tropical plants, and rice was little used in the Pacific, except in the Mariana Islands in northern Micronesia.
Around 1500 BC, another movement led from Indonesia to the shores of New Guinea, Melanesia, and beyond to the Pacific islands.
The Austronesians were undoubtedly the first great navigators in human history.
In 2010, Hiria Ottino and 5 crew members, on O Tahiti Nui Freedom, a simple outrigger and sail pirogue, retraced the migration route in 123 days, in the opposite direction: Tahiti, Cook Islands, Tonga, Fiji, Vanuatu, Solomon Islands, Papua New Guinea, Palau, Philippines, and China.
Pottery and migration routes The Austronesian populations who settled in Oceania were not only farmers and navigators, they were also potters. Several cultural areas have been identified, facilitating the differentiation and dating of migration waves.
Lapita from Melanesia and Polynesia
Father Otto Meyer was the first to discover these potteries in 1909 on the island of Watom, in the Bismarck Archipelago (now in Papua New Guinea). In 1917, the geologist Maurice Piroutet also found some in a locality in northern New Caledonia called Lapita. This name was subsequently adopted by archaeologists to designate the whole of this pottery and the associated cultural complex, which characterizes an area stretching from the Bismarck Archipelago in the west to Tonga and Samoa in the east. The pottery features intricate geometric patterns impressed into the clay by small, toothed stamps.
Throughout the 20th century, various excavations uncovered further examples of this pottery throughout the western Pacific (or Near Oceania), including the Solomon Islands, Vanuatu, New Caledonia, Fiji, Wallis and Futuna, and as far as Samoa.