The Austronesian expansion into Asia & Oceania
The broader question concerning the entry of humans into Southeast Asia and Oceania has remained controversial. Land bridges presented a different map from today with Borneo joined to the mainland and forests connecting present-day Sumatra with Asia. The Torres Strait islands were settled in about 3000 BP.
Modern humans have lived in South-East Asia for about 70,000 years, but DNA analysis (Vietnam, Cambodia, Thailand, and Myanmar) indicates the first farmers probably came from China the new genes flowing into the indigenous hunter-gatherer populations about 4,500 years ago coinciding with the appearance of rice paddies, tools, and pottery made in South China styles. A second gene pulse flowed from China to South-East Asia a couple of thousand years later.
Austronesia is the region where the Austronesian language (an ancient language group like Indo-European – see Language) is spoken by about 386 million people. Mostly north of Australia it extends from Madagascar in the east to Easter Island in the west and is divided into three sub-regions: Taiwan, maritime Southeast Asia, and Oceania (Micronesia, Melanesia, and Polynesia). Also in the region are Singapore, the Pattani region of Thailand, the Cham areas of Vietnam (the former Champa kingdom which covered central and southern Vietnam), Cambodia, and Hainan, China.
Recent studies have located an archaic and extinct group of hominins from Denisova in Siberia called the Denisovans whose DNA is present in Australian Aboriginals and New Guineans. Ancient DNA like this provides valuable indication of ancient gene flow and therefore migration patterns. Analysis of Denisovan DNA in 2011 indicated that Southeast Asia was settled by modern humans in multiple waves, the evidence being consistent with the hypothesis of a southern route migration. Another study has detected the genetic signature of the Mamanwa (a Negrito group from the Philippines) with a divergence time of at least 35,000 years ago while Indian connections dating back about 4,000 years might relate to pre-European trade with island SE Asian peoples through the Indonesian Archipelago rather than directly with India. A subsequent Y-chromosome study has found divergence times dating back about 50,000 years thus excluding the Y chromosome as providing evidence for recent gene flow from India into Australia.
Linguistic analysis has given rise to two major theories of human migration in this region, the ‘Out of Taiwan’ and ‘Out of Sundaland’ theories.
The ‘Out of Taiwan’ model suggests the dispersal of an agricultural people from Taiwan into insular Southeast Asia, Melanesia, and, ultimately, the remote Pacific. Commencing in about 5,000-2,500 BCE Austronesian peoples of maritime Southeast Asia sailed eastward entering Melanesia and Micronesia between 1200 BCE and 500 CE respectively, Polynesia by 1,000 BCE also Easter Island by 300 CE, Hawaii by 400 CE, and New Zealand by about 1280 CE. Westward expansion had been through maritime Southeast Asia reaching Madagascar by 0–500 CE.
Archaeological studies of peoples living in South Pacific islands such as Vanuatu and Tonga have been associated with the Asian Lapita culture which populated remote islands of the Pacific about 3,000 years ago. Today, all south Pacific Islanders possess DNA from Papua and East Asia but analysis of ancient DNA of skeletons from Vanuatu and Tonga indicate a discretely Asian origin with resemblance to the DNA of Aboriginal people of Taiwan and the northern Philippines indicating Papuan mixing followed in a second wave. This challenges the use of the terms Melanesian and Polynesian to describe peoples from different parts of the Pacific. Genetic analysis indicated a first wave of Lapita seafarers soon followed by a second wave of Papuans, mainly men moving from the New Guinea-Solomons region marrying the Asian women.
For Vanuatu it is in late Lapita times 2,800 to 2,700 years ago when populations were small but it may have been much later in Fiji and Polynesia, the population moving from Tonga and Samoa to the eastern Pacific Islands of Hawaii and Tahiti about 1000 years ago then about 700 years ago travelling south to settle as the Maori population in New Zealand.
In the Micronesian Caroline Islands of the western Pacific, about 1500 km north of New Guinea lies the island of Pohnpei. The earliest settlers on the island were probably Lapita culture people from the Southeast Solomon islands or the Vanuatu archipelago. Here there is the archaeological site of the city of the enigmatic Nan Madol, one-time capital of the Saudeleur Dynasty until about 1628. It is remarkable for its monumental architecture of walls, artificial islands, and canals. It was probably established in the first or second century CE, islet construction beginning in the 8th to 9th century, had started and megalithic construction marking the height of civilization around 1180–1200 CE. Two mythical brothers are said to have arrived to build a temple to agriculture, marrying local women and founding a ruling dynasty lasting more than 12 generations and lasting c.1100-1628 and ending with the invasion of Isokelekel, another semi-mythical foreigner, who replaced the Saudeleur rule with the more decentralized nahnmwarki system in existence today. The Pohnpeian language is an indigenous Micronesian language and is the second most widely spoken native language of the Federated States of Micronesia.
The ‘Out of Sundaland’ theory relates migrations to an earlier period – the inundation of ancient Sundaland (which included the Asian landmass extending to Borneo and Java) with migrations from the Philippines north to Taiwan 15,000 to 7,000 BP after the last Ice Age when rising sea levels flooded Sunda Peninsula creating the Java and South China Seas and the islands of the Indonesian and Philippine archipelagos.
Eastern Indonesia has people of both Asian and Papuan ancestry and genome analysis supports linguistic, archaeological and genetic evidence indicating a pre-Austronesian Papuan presence with an eastward spread of Austronesian-speaking farmers beginning about 4,000 to 3,000 years ago.
Three peoples inhabit the region: those of SE Asia, the dark-skinned Melanesians, and the Polynesians in the east. Polynesians are assumed to be descendants of people with similar physical features who migrated from South-East Asia but their route into Polynesia is obscure. A recent study indicates arrival of Polynesians in Vanuatu, New Caledonia, and Fiji pre-dated that of the Melanesians from further west who are the most prominent people living there today.
Skulls found at Teouma were similar in appearance and measurements to those of tall present-day Polynesian and Asian populations.A study published in 2015 describing Lapita culture skeletons in about 70 graves of a 3,000-year-old Teouma cemetery, discovered in 2004, in Vanuatu just outside the capital of Port Vila reveals clues to the origins of Polynesian people. The study suggests Polynesians migrated from South-East Asia through Melanesia and into Polynesia. There appears to have been minimal mixing between early generations of Polynesians and the Melanesian populations of Papua New Guinea and the Solomons who had inhabited this region for the previous 50,000 or so years.
From about 1,500 BCE for about 1,500 years there were major transportation networks (trade routes) passing from Western Asia, the Mediterranean and Africa through to the Indian subcontinent and China. Minor trade routes apossibly extended this trade into the Indonesian Archipelago. It must be assumed that the transport of plants by maritime traders and explorers in the Indonesian archipelago and west Pacific has ben in operation for at least 3,000 years (see Pre-European settlement plant introduction).