Prehistory of Australia
The prehistory of Australia is the period between the first human habitation of the Australian continent and the colonisation of Australia in 1788, which marks the start of consistent written documentation of Australia. This period has been variously estimated, with most evidence suggesting that it goes back between 50,000 and 65,000 years. This era is referred to as prehistory rather than history because knowledge of this time period does not derive from written documentation. However, some argue that Indigenous oral tradition should be accorded an equal status.
Human habitation of the Australian continent began with the migration of the ancestors of today's Aboriginal Australians by land bridges and short sea crossings from what is now Southeast Asia. It is uncertain how many waves of immigration may have contributed to these ancestors of modern Aboriginal Australians. The Madjedbebe rock shelter in Arnhem Land is perhaps the oldest site showing the presence of humans in Australia. The oldest human remains found are at Lake Mungo in New South Wales, which have been dated to around 41,000 years ago.
At the time of first European contact, estimates of the Aboriginal population range from 300,000 to one million, with a more recent estimate of over 3 million people in the area that is now Australia. They were complex hunter-gatherers with diverse economies and societies. There were about 600 tribes or nations and 250 languages with various dialects. Certain groups engaged in fire-stick farming, fish farming, and built semi-permanent shelters. The extent to which some groups engaged in agriculture is controversial.
The Torres Strait Islander people first settled their islands around 4,000 years ago. Culturally and linguistically distinct from mainland Aboriginal peoples, they were seafarers and obtained their livelihood from seasonal horticulture and the resources of their reefs and seas. Agriculture also developed on some islands and villages appeared by the 1300s.
Arrival
The earliest evidence of humans in Australia has been variously estimated, with most scholars, as of 2023, dating it between 50,000 and 65,000 years BP.Recent genomic studies indicate that all non–sub-Saharan African populations, including present-day Aboriginal Australians, carry Neanderthal DNA acquired through a single interbreeding event in Europe between approximately 51.5 and 43.5 thousand years ago. If correct, this genetic evidence would constrain the timing of the ancestry of present-day Sahul populations to after ~50 kya, making it unlikely that a ~65 kya arrival contributed to the modern gene pool. However, earlier anatomically modern human occupations not ancestral to living populations cannot be ruled out.
There is considerable discussion among archaeologists as to the route taken by the first migrants to Australia, widely taken to be ancestors of the modern Aboriginal peoples. Migration took place during the closing stages of the Pleistocene, when sea levels were much lower than they are today. Repeated episodes of extended glaciation during the Pleistocene epoch resulted in decreases of sea levels by more than 100 metres in Australasia. People appear to have arrived by sea during a period of glaciation, when New Guinea and Tasmania were joined to the continent of Australia. The continental coastline extended much further out into the Timor Sea, and Australia and New Guinea formed a single landmass, connected by an extensive land bridge across the Arafura Sea, Gulf of Carpentaria and Torres Strait. Nevertheless, the sea still presented a major obstacle so it is theorised that these ancestral people reached Australia by island hopping. Two routes have been proposed. One follows an island chain between Sulawesi and New Guinea and the other reaches North Western Australia via Timor. Rupert Gerritsen has suggested an alternative theory, involving accidental colonisation as a result of tsunamis. The journey still required sea travel, however, making them some of the world's earliest mariners.
In the 2013 book First Footprints: The Epic Story of the First Australians, Scott Cane writes that the first wave may have been prompted by the eruption of Toba, and if they arrived around 70,000 years ago, they could have crossed the water from Timor, when the sea level was low – but if they came later, around 50,000 years ago, a more likely route would be through the Moluccas to New Guinea. Given that the likely landfall regions have been under around 50 metres of water for the last 15,000 years, it is unlikely that the timing will ever be established with certainty.
Dating of sites
The minimum widely accepted time-frame for the arrival of humans in Australia is placed at least 48,000 years ago. Many sites dating from this time period have been excavated. In Arnhem Land Madjedbebe fossils and a rock shelter have been dated to around 65,000 years old, although a study in 2020 argues that this dating is unreliable. According to mitochondrial DNA research, Aboriginal people reached Eyre Peninsula 49,000–45,000 years ago from both the east and the west.Radiocarbon dating suggests that they lived in and around Sydney for at least 30,000 years. In Parramatta, Western Sydney, it was found that some Aboriginal peoples used charcoal, stone tools and possible ancient campfires. Near Penrith, a far western suburb of Sydney, numerous Aboriginal stone tools were found in Cranebrook Terraces gravel sediments having dates of 45,000 to 50,000 years BP. This would mean that there was human settlement in Sydney earlier than thought.
Archaeological evidence indicates human habitation at the upper Swan River, Western Australia by about 40,000 years ago. A 2018 study using archaeobotany dated evidence of human habitation at Karnatukul in the Carnarvon Range in the Little Sandy Desert in WA at around 50,000 years, and it was shown that human habitation had been continuous at the site since then.
Tasmania, which was connected to the continent by a land bridge, was inhabited at least 40,000 years ago. The oldest known site is Wareen Cave, dated to this time.
Migration routes and waves
A 2021 study by researchers at the Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage has mapped the likely migration routes of the peoples as they moved across the Australian continent to its southern reaches of what is now Tasmania, but back then part of the mainland. The modelling is based on data from archaeologists, anthropologists, ecologists, geneticists, climatologists, geomorphologists, and hydrologists, and it is intended to compare the modelling with the oral histories of Aboriginal peoples, including Dreaming stories, as well as Australian rock art and linguistic features of the many Aboriginal languages. The routes, dubbed "superhighways" by the authors, are similar to current highways and stock routes in Australia. Lynette Russell of Monash University sees the new model as a starting point for collaboration with Aboriginal people to help uncover their history. The new models suggest that the first people may have first landed in the Kimberley region in what is now Western Australia about 60,000 years ago, and had settled across the continent within 6,000 years.Archeological evidence indicates that the ancestors of today's Aboriginal Australians first migrated to the continent 50,000 to 65,000 years ago. Genomic studies suggest that the peopling of Australia happened between 43,000 to 60,000 years ago.
DNA studies have suggested that the ancestors of Aboriginal Australians belonged to the southern route dispersal following the "out of Africa" exit, which expanded into the South and Southeast Asia region and subsequently diverged rapidly into the ancestors of Ancient Ancestral South Indians, Andamanese, East Asians, other Australasians, such as Papuans.
It is unknown how many populations settled in Australia prior to European colonisation. Both "trihybrid" and single-origin hypotheses have received extensive discussion. Keith Windschuttle, known for his belief that Aboriginal pre-history has become politicised, argues that the assumption of a single origin is tied into ethnic solidarity, and multiple entry was suppressed because it could be used to justify white seizure of Aboriginal lands, but this hypothesis is not supported by scientific studies.
Changes c. 4000 years ago
differences are being studied to find possible answers, but there is still insufficient evidence to distinguish a "wave invasion model" from a "single settlement" one.A 2012 paper by Alan J. Redd et al. on the topic of migration from India around 4,000 years ago notes that the indicated influx period corresponds to the timing of various other changes, specifically mentioning "The divergence times reported here correspond with a series of changes in the Australian anthropological record between 5,000 years ago and 3,000 years ago, including the introduction of the dingo; the spread of the Australian Small Tool tradition; the appearance of plant-processing technologies, especially complex detoxification of cycads; and the expansion of the Pama-Nyungan language over seven-eighths of Australia". Although previously linked to the pariah dogs of India, recent testing of the mitochondrial DNA of dingoes shows a closer connection to the dogs of Eastern Asia and North America, suggesting an introduction as a result of the Austronesian expansion from Southern China to Timor over the last 5,000 years. A 2007 finding of kangaroo ticks on the pariah dogs of Thailand suggested that this genetic expansion may have been a two-way process.
The dingo reached Australia about 4,000 years ago, and around the same time there were changes in language, with the Pama-Nyungan language family spreading over most of the mainland, and stone tool technology, with the use of smaller tools. Human contact has thus been inferred, and genetic data of two kinds have been proposed to support a gene flow from India to Australia: firstly, signs of South Asian components in Aboriginal Australian genomes, reported on the basis of genome-wide SNP data; and secondly, the existence of a Y chromosome lineage, designated haplogroup C∗, with the most recent common ancestor around 5,000 years ago. The first type of evidence comes from a 2013 study by the Max Planck Institute for Evolutionary Anthropology using large-scale genotyping data from a pool of Aboriginal Australians, New Guineans, island Southeast Asians and Indians. It found that the New Guinea and Mamanwa groups diverged from the Aboriginal about 36,000 years ago, and also that the Indian and Australian populations mixed well before European contact, with this gene flow occurring during the Holocene. The researchers had two theories for this: either some Indians had contact with people in Indonesia who eventually transferred those genes from India to Aboriginal Australians, or that a group of Indians migrated all the way from India to Australia and intermingled with the locals directly.
However, a 2016 study in Current Biology by Anders Bergström et al. excluded the Y chromosome as providing evidence for recent gene flow from India into Australia. The study authors sequenced 13 Aboriginal Australian Y chromosomes using recent advances in gene sequencing technology, investigating their divergence times from Y chromosomes in other continents, including comparing the haplogroup C chromosomes. The authors concluded that, although the results do not disprove the presence of any Holocene gene flow or non-genetic influences from South Asia at that time, and the appearance of the dingo does provide strong evidence for foreign arrivals, the evidence overall is consistent with a complete lack of gene flow, and points to indigenous origins for the technological and linguistic changes. Gene flow across the island-dotted -wide Torres Strait is plausible and while Y chromosome divergence times are consistent with a lack of gene flow across the Strait since its formation due to rising sea levels, the authors assert that the Torres Strait Islander ancestry of the men from which the times were derived means external contact occurred more recently. It could not be determined from the study when within the last 10,000 years this may have occurred – newer analytical techniques have the potential to address such questions.