From Empire of the Winds: The Global Role of Asia’s Great Archipelago, by Philip Bowring (I.B. Tauris, 2018), Kindle pp. 39-41:
Even at the lowest sea levels of the last ice age, there was deep water between Bali on the edge of the Sunda Shelf [SE Asia] and the Sahul Shelf [Australia, New Guinea]. But the distances were small enough for humans – though not for many animal species – to cross. It was during the last great glaciations that modern humans reached Australia, most likely arriving via Wallacea [between Borneo & New Guinea]. New Guinea was reached about the same time and became, around ten thousand years ago, probably the first place on earth – long before Egypt or Mesopotamia – where settled agriculture was practised.
… The sea rise also created a genetic and cultural rift. By modern times there was a clear racial divide between the Malay-Polynesians, speaking Austronesian languages, and Papuan-Melanesian physical types and cultures. Despite their remarkable east to west dispersal, the former left little trace in lands that were relics of the Sahul Shelf other than in the Bismarck Archipelago. However, some Melanesians remained further west. Findings from Niah cave in Sarawak dated to about 40,000 years ago and at Tabon on Palawan dated to 25,000 years ago have genetic characteristics similar to ancient Australians and Melanesians. So it is likely that the first Homo Sapiens in the region were of the same stock as the Australo-Melanesians who settled the forests and highland valleys of New Guinea and the bush country and great deserts of Australia. The Tabon caves were inhabited from around 30,000 BP, but while they now overlook the sea they were once on a hillside far from the shore. Thus far, no similar finds have been made on other islands, which may suggest that Tabon man walked there and that early man in that region had yet to gain sufficient skills to cross from Palawan to Mindanao or the Visayas.
The deep water gaps between Wallacea and the Sahul and Sunda landmasses had a huge impact on fauna and flora. Until later introduced by humans, large placental mammals never crossed that divide from Sundaland to Wallacea nor did large marsupials move in the other direction. Wallacea had its own separate but rather limited indigenous fauna and flora due to its weak links to the great landmasses and the distance in time since it had drifted from Gondwanaland [continental Southern Hemisphere].
The ending of the last ice age must have been a catastrophe for many of the people of Sundaland, the relatively flat land between what is now the Asian mainland and the coasts of Sumatra, Java and Borneo. While global warming enabled areas such as northern Europe to become habitable, in Asia it destroyed large numbers of human settlements in a region which previously should have been very conducive to habitation. By the same token, the creation of many islands and a huge expansion of coastlines produced the environment for the world of the Nusantarians, living on and by the sea, developing sailing craft and navigational prowess and building the coastal exchange networks which eventually evolved into ocean-spanning movements. They were behind the expansion of human settlement and of trade around half the globe. The same people, originating from Nusantaria, settled almost every island between Rapa Nui (Easter Island) and Madagascar, between Taiwan and New Zealand.
Today, the majority of people from Nusantaria are defined as ‘Austronesians’ – a Greek-derived word meaning ‘southern islands’ but now applied to a language group. Austronesian is in the first instance a linguistic marker though also with shared genetic and cultural characteristics. As a language group it was the world’s most widely dispersed until Europeans settled the Americas 500 years ago. Austronesian expansion across the Pacific and Indian oceans was enabled primarily by mastery of the sea and driven forward by the confines of their many, mostly rugged, islands.
Far Outliers 