Human origin & migration

Introduction – Human Origin and Migration

Our understanding of long-term human history is undergoing constant revision in as new evidence, mostly genetic, emerges about human origin and migration.^[49]

Until relatively recently (c. 2020) the prevailing view was that Homo sapiens evolved in eastern Africa about 200,000 to 150,000 years ago, undergoing a cognitive revolution around 60,000 years ago at about the same time as a migration out of Africa to colonize the world, replacing archaic humans as they did so. This ‘out of Africa’ narrative replaced a former model known as ‘multiregionalism’ which claimed that archaic humans were distributed across Africa and Eurasia at least a million years ago separate groups evolving independently into anatomically modern humans. Anatomically modern humans differed from archaic humans by having flat, delicate faces, prominent chins and spherical brain cases.

Both of these theories are currently under critical revision and this revision of earlier views includes: the distinction between anatomical and behavioral modernity (current evidence suggests modern cognition occurred at about the same time as modern anatomy) ; between archaic and modern anatomies (this distinction is becoming blurred); the early human local origin in eastern Africa around 200,000 years ago (replaced by an origin closer to 315,000 years ago and possibly as much as 500,000 years with the transition from archaic to modern occurring in different parts of a ‘Greater Africa’ in a form of ‘African multiregionalism’ with no single centre of origin). At about this time flat leaf-shaped hand-axes used for about 700,000 years changed to a more elaborate toolkit of smaller and finely pointed tools and weapons and it is this that is taken by some as the dawn of the modern mind.

Although the closest human relatives, the Neanderthals and Denisovans, became extinct tens of thousands of years ago, most humans today have traces of DNA from one or both. We are uncertain of our last direct ancestor. It appears that there was no common ancestor of humans and Neanderthals (our sister species). The Denisovans are more closely related to Neanderthals than ourselves so our last direct ancestor was the species that gave rise to us and the Neanderthal Denisovan lineage. This might push the split between modern humans and Neanderthal/Denisovans back as far as 765,00 years. Early Homo sapiens is possibly less a species than a diverse clade displaying wide physical variation.

Genetic anthropology (palaeogenetics)

Since the late 1980s the paths and dates of these ancient migrations across the world have been coming into focus due, in large part, to the analysis of genetic markers (mutations that remain in all subsequent offspring) on female mitochondrial DNA (mt DNA) and male Y chromosomes (Y-DNA). Genetic anthropology, as it is called, uses these markers to identify genetic lineages, where these lineages originated, and their approximate age. This, together with ever-improving archeological and linguistic research, has given us an insight into probable prehistoric human migration patterns across the globe.

In 1987 the first human family tree was produced based on mtDNA and tracing all humans back to a single hypothetical female ancestor known as ‘Eve’.

Routine genetic ancestry testing using DNA from saliva is vastly improved when using bone extracts that analyze whole ancient genomes, greatly improving reconstructions of prehistoric migrations and mixing of populations in the past 5,000 years and beyond. This tool has only become available in the last decade.

Ancestral humans

Current theory suggests that it is African australopithecines, dating from 3 to 4.4 Mya, that evolved into the earliest members of genus Homo.

In 2014, 900,000-year-old footprints of human ancestors were discovered on Happisburgh beach in Norfolk, UK after soft, sedimentary estuary rocks were revealed after a heavy storm.^[52] The 49 footprints created by at least 5 individuals (adults and children) are the earliest evidence of human predecessors in northern Europe at a time when Britain was connected to the continent. Stone tools and bones in this area also date back around 800,000 years or more. This hominin was probably Homo antecessor or Pioneer Man. The previous oldest records were stone tools found in southern Italy and a tooth found in Spain – and, in Britain, stone tools found in Lowestoft that date to about 700,000 BP. Footprints in Tanzania date back about 3.5 M years.

The genus Homo

So, human beings (genus Homo) arose in Africa about 3 to 4.4 Mya, diversifying and migrating out of Africa to colonize other continents as modern humans, Homo sapiens, about 80-90,000 years ago.

Migration across the Arabian Peninsula was probably repeated many times. Today’s arid Nefud desert of the Arabian Peninsula interior was once the site of grassland and lakes. Archaeological evidence suggests there have been at least five hominin expansions into this Arabian interior, coinciding with brief ‘green’ windows of reduced aridity approximately 400, 300, 200, 130–75 and 55 thousand years ago. The oldest tools found here were stone axes crafted in a style associated with archaic humans known as Homo erectus or Homo heidelbergensis, who lived in Africa and Asia. Then, around 200,000 years ago, flaked tools associated with our species, Homo sapiens, appear alongside these stone axes.^[54]

About 100,000 years ago there were at least five living species of human: the short, stocky, heavy-browed and cave-dwelling Homo neanderthalensis from cool-climate northern Europe branched off from modern human line 50-700,000 BP. Though Neanderthals are now extinct, part of their genome survives. All present-day non-Africans have at least 2% of Neanderthal ancestry. Around 50,000 years ago, modern humans mated with Neanderthals, and their descendants carried those genes all over the world. The last geological record dates to c. 32,000 BP in Gibraltar caves; the slight H. solensis in Java; the dwarf one-metre tall H. floresiensis on the island of Flores in East Java (discovered in 2004) about 3′ tall, possibly exhibiting island dwarfism; H. denisova from Siberian Russia who lived with the Neanderthals, splitting from the Neanderthal line in about 400,000 BP (discovered in 2008), with evidence of interbreeding in Aboriginal, Indian, and Chinese DNA; and the massive short, muscular, and heavy-browed Homo erectus (Upright Man) with archaeological remains extending from 1.5-2 million years ago to about 50,000 BP. H. erectus was widespread from Europe to Asia the remains found in China and known as Peking Man dating back about 750,000 years ago^[19] while some estimates of Indonesia’s Java Man date back to about 1.9 million years. Several additional species probably evolved among the populations that remained in East Africa, H. naledi whose remains in South Africa date to the Middle Pleistocene 335,000–236,000 years ago is of uncertain rlationship to other species.

Our complex cognitive and social capacities are also believed to have emerged around 100,000 years ago or earlier.

Modern humans (Homo sapiens)

Up to 2017 the earliest modern humans, Homo sapiens, dated by genetic analysis and fossils, have been recovered from Omo Kibish (c. 195,000 years old), and Herto, (c. 160,000 years old) both in modern-day Ethiopia, East Africa.^[27][42] Research published in 2017 on remains from the archaeological site Jebel Irhoud in Morocco suggests that Homo sapiens spread across the entire African continent more than 100,000 years earlier than previously thought and that important changes in our biology and behaviour had already taken place across most of Africa by that time. There are differences in the structure of the cranium, placing them somewhere between Homo erectus and African archaic Middle Pleistocene hominins. In this way it challenges the hypothesis that Homo sapiens derived from a later intermediate species that lead to the emergence of both the modern human and Neanderthal lineages. Modern Eurasian s contain 2-7% Neanderthal DNA. This suggests that our facial shape was established early in our evolutionary while cognitive functions may have appeared later. It is likely that more archaic forms of hominins coexisted with the early representative of our species. The path to being the lone surviving hominid species appears to be anything but linear.^[38][39]

Behavioural modernity

One of the most interesting, little-explored, and controversial aspects of human evolution is the cognitive transition that has occurred from late primate brain to that of modern humans. It is clear that Homo sapiens today has behavioral and cognitive traits that distinguish it from hominins and other primates. These include cultural, artistic, and symbolic sophistication, language, the capacity for abstract thought and its communication, ratiocination etc. But how and when did this transition occur? How are our innate abilities linked to the cultural development of physical and intellectual tools like technology, language, and mathematics?

Out of Africa

Evidence from mitochondrial DNA suggests the origin in southern Africa of anatomically modern humans about 200,000 BP in a former wetland south of the Zambezi River – an area that crosses northern Botswana and heads into Namibia in the west and Zimbabwe in the east. Then, about 130,000 years ago the climate began to change, first opening up a green migration corridor to the northeast, and 20,000 years later to the southwest. This climatic data matches the divergence we see in the genetic data around this time increasing the likelihood that this is when the first migrations out of our homeland began although additional archaeological and nuclear DNA evidence is required.^[51

Recent studies suggest that modern humans did not merge from a restricted cradle in sub-Saharan Africa at a precise point in time about 300,000 BP. Rather, the round brain case, pronounced chin and a small face, didn’t appear in combination until about 100,000 years ago, the result of isolated populations scattered across Africa (segregated by diverse habitats and shifting environmental boundaries, such as forests and deserts), that would occasionally interbreed.^[44][47]

From the archaeological record it is clear that during the years 125,000-60,000 BP there were several migrations of H. sapiens out of Africa. Research at the Bacho Kiro cave in Bulgaria indicates that modern humans were in Europe at least 45,000 years ago^[50] and that they probably taught Neanderthals to make necklaces out of bear teeth.

Neanderthals H. neanderthalensis (Neanderthal Man) lived in Europe for hundreds of thousands of years, interbreeding with modern humans when they met, but dying out a few thousand years later. The last clear dating of their presence is about 40,000 years old.^[50]

Archaeological artefacts indicate several waves of H. sapiens on the Arabian peninsula dating back about 125,000 BP but modern genetic research now supports the ‘Out of Africa’ theory claiming that the unique lineage giving rise to all anatomically modern humans left Africa relatively recently, about 60,000-70,000 BP but in 2018 the discovery of a fossilized modern human finger bone at Al Wusta on the Arabian Peninsula dated to 85,000 BP became the earliest archaeological record of anatomically modern humans outside Africa and the Levant (modern human maxillae at the Levantine sites of Skhul and Qafzeh date to around 90,000 to 120,000 years BP).^[41] The finger bone places on a more intuitive time scale the arrival of modern humans in Australia in about 65,000 BP.

European foragers, farmers, & steppe pastoralists

In his book Who we are and how we got here (2018) David Reich reconstructs the histories of modern Europeans, Indians, Native Americans, East Asians and Africans. He shows how modern populations in Europe and north India derive from mixing of native populations with Yamnaya people from the steppes north of the Black Sea and the Caspian Sea some 5,000 years ago, in separate migrations to the west and the east. Corded ware culture, known well to archaeology, is a stage in this westward migration. Yamnaya culture spread westwards around 3300–2600 BC bringing Indo-European languages with it.

Reviewing the book for the New York Times, Jared Diamond points out that

‘Archaeology indicates that farming reached Greece from Anatolia (modern Turkey) 9,000 years ago, and spread northwest to Britain. The prevalent view has thus been that invading Anatolian farmers intermarried with Europe’s original hunter-gatherers, and their genes became diluted with hunter-gatherers’ genes as the farmers spread northwest. According to that view, the modern Europeans most closely approximating Europe’s original hunter-gatherers would be the red-haired blue-eyed Irish on the west coast of Ireland. But genetic discoveries have revealed a third ancient group, whose genes dominate modern Northern Europeans. That group consisted of herders from the Asian steppes, whose skeletons and genes are known from their burial mounds called kurgans. It turns out that those herders contributed about half the genes of Northern European and British skeletons beginning around 5,000 years ago. Evidently, the herders somehow outbred or exterminated most of Europe’s original farmers. How on earth could small numbers of herders have overwhelmed dense farmer populations? A clue is that 7 percent of ancient DNA samples from Europe and the steppes contain DNA of the plague microbe that caused medieval Europe’s Black Death. Perhaps steppe peoples acquired plague, developed some immunity with exposure, and transmitted it to unexposed European farmers, thereby decimating them. It would be ironic if Europe’s first farmers succumbed to an introduced disease, because other diseases introduced by European colonists of the New World after 1492 equally decimated Native American populations.’

The significant role of steppe pastoralists in European ancestry is a genetic revelation.

From Africa to Sahul

The first analysis of a complete Aboriginal genome was in 2011 and it included a synthesis of the accumulated genetic evidence noting Australian Aboriginals as one of the oldest continuous lineages out of Africa, the journey from Africa apparently passing across the Arabian Peninsula, along the coast of India, through south-east Asia and down the Malayan Archipelago then, aided by low sea levels and ancient land bridges that no longer exist, splitting into two, one line settling in present-day Papua New Guinea and the other Australia, although at that time these countries were part of the single land mass Sahul. There was an extensive land bridge across the Arafura Sea, Gulf of Carpentaria, Joseph Bonaparte Gulf, and Torres Strait which at that time would have been savanna and woodland.

Evidence from mtDNA suggests that Australia and New Guinea were colonized jointly or that the populations have subsequently mixed after occupation.^[3][14] The split into Aboriginal and New Guinea peoples is presumed to have been quite ancient as Aboriginals are more closely related to southern Indians than to the New Guineans.

A 2007 analysis of mtDNA and Y-DNA showed no continuity with former H. erectus. As only the earliest founding genetic material is shared with Asia then this indicates long-term isolation of Aboriginal populations and the likelihood of a single founder colonisation. The migration time from SW Asia to Australia is estimated at about 5,200 years.^[16]

A 2016 Cambridge University study^[34] sampled the genomes of 83 Aboriginal Australians from the Pama-Nyungan-speaking language group covering 90 per cent of the continent, together with 25 Highland Papuans. Key findings include dating the departure of modern humans from Africa about 72,000 years ago, that Papuan and Aboriginal ancestors left Africa around 72,000 years ago, split from the main ancestral group around 58,000 years ago, arriving on Sahul about 50,000 years ago (the data indicating a single wave of colonization), their DNA including that of Neanderthals, Denisovans and another extinct hominin. Papuans and Aboriginals then split around 37,000 years ago, long before Australia and Papua-New Guinea separated about 8,000 years ago. By 31,000 years ago, most Aboriginal communities were genetically isolated from each other, giving rise to exceptional genetic diversity. Though the exact entry point is unclear the data reveal an expansion of people from Cape York.

There is remarkable genetic diversity between Aboriginal people of the east and west of Australia (greater than that between people living in Siberia and the Americas) possibly a consequence of the last Ice Age around 30,000 to 20,000 years ago.

Migration route and time of arrival in Sahul

It is remarkable that while Homo sapiens is first recorded in northern Europe c. 42,000-43,000 BP, Britain about 25,000 BP, North America about 18,000 BP,^[26] South America about 12,000 BP – Aborigines had populated Australia by about 65,000 BP reaching Tasmania in about 35,000 BP.

Up to 2017 archaeological dating using optically stimulated luminescence (OSL) dated the occupation of the Kimberley and Arnhemland to between 53,000 and 60,000 BP, this region possibly occupied for some time before the rest of the continent.^[11] Genetic evidence indicates an arrival date of 55,000 ± 10,000 years^[2] ago which aligned well with archaeological evidence at this time, the earliest artefacts dating from 53,000 to 61,000 BP in deposits of the Madjedbebe (former Malakunanja II) and Nauwalabila rock shelters in Arnhem Land’s Kakadu National Park.^[13] In 2017 these figures were revised. About 300 kilometres east of Darwin in Mirarr Country excavations at the Madjedbebe rock shelter near Kakadu National Park, on a sandy plain at the base of the Arnhem Land escarpment, have revealed a wealth of artefacts including ground-edge axes, grindstones, flints and ochre as well as evidence of fireplaces. They include the world’s oldest-known ground-edge axe head — one made by grinding rather than flaking. This is the earliest evidence of humans in Australia at one of the most significant cultural and archaeological sites in the world. Optical and other dating places the earliest artefacts at 65,000 ± 5000 years. This is important for the dating of human exodus from Africa and the genetic interaction with Neanderthals, Denisovans, and other possible hominins.^[40]

Modern research is currently assessing factors like climate change and geography that likely influenced the pattern and timing of this global migration, the migration out of Africa possibly triggered by climate change induced coastal retreat of sea levels as ice was locked up in the poles during an advancing ice age.^[20][21] Though Aboriginal history has little reference to maritime activity it is possible that the crossing to Australia is the world’s first clear evidence of the use of watercraft in travelling between land masses.

The world’s oldest-known figurative art occurs in caves in the Indonesian province of Kalimantan which contain thousands rock art images of animals, hand stencils and symbols dated from 40,000 to 52,000 BP. However, one painting in Borneo, probably depicting the wild cattle known as banteng, was created at least 5,000 years earlier than animal paintings on the Indonesian island of Sulawesi and caves in France. Hand stencils are presumed to be at least 37,500 years old. The subject of the paintings shifted from animals to humans at the peak of the Ice Age between 20,000-21,000 years ago (a change that also occurred in Europe, and in Australia at a later time). The similarity of art between Borneo and Sulawesi suggest modern humans may have taken a northerly route through South-East Asia to Australia at a time when Borneo was still part of the Asian mainland.

‘It is now evident that rock art emerges in Borneo at around the same time as the earliest forms of artistic expression appear in Europe in association with the arrival of modern humans (45,000–43,000 calibrated years). Thus, similar cave art traditions appear to arise near-contemporaneously in the extreme west and extreme east of Eurasia. Whether this is a coincidence, the result of cultural convergence in widely separated regions, large-scale migrations of a distinct Eurasian population or another cause remains unknown.’^[46]

The crossing from Sunda to Sahul 65,000 years ago would have required just a few island hops of 30-90 km. From Timor’s mountains, with views up to 175 km away, it may have been possible to see smoke from fires produce by lightning strikes on Sahul and to gain additional hints of land to the south from bird behaviour and other factors.^[12]

Two paths of entry from Sunda have been suggested, one a southern route through the islands of Flores and Timor, the other more northerly passing through Sulawesi – we may never know for sure.^[1] Between Sunda and Sahul was an ocean trench at least 70 km wide at the transition between the Sunda and Sahul tectonic plates and forming a biogeographical transitional frontier, known as Wallace’s Line or Wallacea (named after Darwin’s contemporary and co-originator of the theory of evolution, Alfred Wallace, who noticed a striking difference in organisms during his mid 19^th century travels in the East Indies) between the plants and animals of Asia (e.g. elephant, tiger, urang-utan) and those mostly from Greater Australia (marsupials, monotremes). Three human species are known to have occupied Sunda: Homo erectus, H. floresiensis (endemic to the island of Flores until about 18,000 BP, now redated to 60,000 to 100,000 BP)) and H. sapiens. Only H. sapiens can be confirmed as completing the short crossing across the strait. The only placental mammals to precede humans across this line were bats and rodents.^[4]

Genetic evidence also suggests that humans were in New Guinea at least 40,000-50,000 years ago when in was attached to Australia, a view supported by findings of stone tools and remnants of yams and pandanus nuts in the Ivane Valley of the New Guinea Highlands dating from 50,000-35,000 BP^[24] – although the first settlement was probably on the now-submerged continental shelf where it is likely that vital clues about the earliest occupation lie tantalisingly concealed on the ocean floor.

Genetic evidence suggests quite a large founding population including several hundred women. The physical differences (notably the much-discussed gracile/robust body shape distinction once taken as evidence for multiple migrations into the continent) are probably the result of adaptations during the period of Australian occupation. Only small groups have subsequently entered the continent with little genetic impact, the diversity of mtDNA lineages indicating long isolation.^[22][23]

Climate and landscape

What was the landscape that greeted these first Aboriginal arrivals?

During the Tertiary, about 1.6 million years ago, forest extended across the centre of the continent but this Holocene phase of cooling and drying now favoured the drought- and fire-resistant eucalypts which often grew with an understory of wattles. Winds were creating the dune systems in the centre and west and there were large fresh to brackish water lakes in the centre of the continent and in today’s Bass Strait and Gulf of Carpentaria.

A catastrophic eruption of Mt Toba in Sumatra occurred between 75,000 and 71,000 years ago with large areas of southeast Asia deforested by lava flows. Dust and tephra ejected from the volcano was dispersed over the Gulf region, Pakistan, India and beyond in what is considered the world’s greatest natural disaster of the last 2 million years.^[1][15]

At the time of Australia’s first human settlement the world was cooling and therefore undergoing rapid environmental change. In the period 50,000 to 10,000 years ago repeated glaciations resultd in sea levels 100–150 m lower than today, the last ice age (LGM) peaking about 18,000 years ago after which sea levels rose again, adjusting to present-day levels about 6,000 years ago. Rising seas after the LGM drowned land bridges and archaeology that lay between the current mainland and Tasmania. Papua New-Guinea and Kangaroo Island, also land between Asia, Java and Sumatra. As much as one seventh of the continent was inundated.

Many natural changes, both climatic and geological, have occurred during the period of human occupation. On the South Australia Victoria border plains there were up to a dozen volcanic eruptions in the last 30,000 years, notably Mt Napier and Mt Eccles. Mount Gambier, like Tower Hill to its east, erupted less than 5,000 years ago. Around 30,000-35,000 BP Lake Eyre was wetter than at any subsequent time and from about 43,000 to 22,000 BP the Lake Mungo region of NSW, site of the oldest human remains found in Australia, would have been a full and fertile lake system.

From about 30,000 BP the climate of the Centre began to dry continuing the process of aridification that had begun in the Miocene about 23 millon years ago, and by the LGM rainfall had halved, there were scouring desert winds and dune formations as the arid zone expanded to occupy nearly 80% of the continent with vegetation largely confined to the northern and eastern margins of the continent. Today’s Great Barrier Reef dates to 6000-8000 BP.

In geological terms the last 10,000 years (known geologically as the Holocene epoch) have exhibited a relatively stable climate.

About 14,000 BP King Island and Cape Otway separated and 13,000 BP this was followed by Wilson’s Promontory and Flinders island, Kangaroo Island being the last major land mass to separate from this coast.p.86. Torres Strait probably formed more recently than Bass Strait isolating New Guinea between 8,000 and 6,500 years ago. Australia was finally isolated as a continent at a time when domestication was gathering momentum in Asia.

Migration within Australia

It was only with the advent of modern radiocarbon dating in the 1960s that is was possible to confirm suspicions that humans had occupied the continent for more than 10,000 years. Archaeological evidence for Aboriginal presence and migration comes from the study and dating of many objects including stone artefacts (lithics), shell middens, caves and rock shelters, earth mounds, rock arrangements, stone and ochre quarries (sometimes worked for many generations), rock and cave art, stone animal traps and hides, carved and stripped trees, hatchet grinding sites, and burial sites. Among the daily implements that remain are the woomera, boomerang, spear, shield, fishing hooks, capes, net bags, basketry, matting, coolamon, bark dish, digging stick, and grinding stones. As a nomadic people the accumulation of physical possessions would have been a burden. Many of the tools needed for daily living would have been improvised at each camp site rather than being carried and as these would probably have been made of perishable materials that would be lost to the archeological record. Much would have depended on resourcefulness resulting from the accumulated knowledge of techniques of food and land management.

Though the number of archaeological sites has increased enormously in recent times the actual pattern of migration following arrival in the north remains uncertain. Perhaps hunting groups chose to follow the seashores which provided a secure year-round supply of food and this is certainly indicated by the many shell middens dotted round the coastline. However, a wealth of archaeological sites dating back more than 40,000 years is scattered over the land mass of Pleistocene Australia so the weight of archaeological evidence suggests ‘saturated settlement’ – the more or less uniform occupation of all landscapes, the interior also being occupied more than 40,000 years ago when rainfall, surface water and food resources were all greater than at present although there were local concentrations of population along the Murray valley and in inlets and bays along the tropical coast.^[6][7] By 47,000 BP most habitats in Greater Australia (Sahul), with the exception of the most arid parts of the Centre, had become occupied^[8][32] and even in the Centre lack of archaeological evidence may be due to the scouring winds and the lack of caves and rock shelters rather than human absence. Certainly the desert margins were inhabited well before the Last Glacial Maximum.^[9]

Studies of the radiocarbon ages of 24 mud wasp nests that were either over or under pigment from 21 anthropomorphic motifs in the style of art known as Gwion, Kiro Kiro or Kujon (formerly ‘Bradshaws’) in the Kimberleys was painted by the ancestors of today’s traditional owners around 12,000 years ago.^[48]

Estimates for the time taken for Aboriginals to walk from Africa to Australia indicate an average rate of 1-4 km a year. If this rate was maintained within Australia then the entire continent would have been occupied in 1,000-4,000 years. Modeling at the Australian Research Council Centre of Excellence for Australian Biodiversity and Heritage suggests the peopling of Sahul may have occurred in as little as 5,000 years in a migration that moved from the far northwest to Tasmania in the southeast. This reasearch also suggests that the total population of Sahul may have reached as many as 6.5 million people.^[53]

Artefacts and fossils from the Warratyi rock shelter in the Flinders Ranges date human settlement of this arid centre area to between 49,000 and 46,000 years ago including reliably dated evidence of human interaction with megafauna that included Diprotodon opatum. The climate at that time was more favourable than that of today being much wetter than at present with lakes and rivers but just entering an extended period of drying. Artefacts excavated at the site push back the earliest-known dates on the development of key bone and stone axe technologies and the use of ochre in Australia. This is the earliest-known use of ochre in Australia and Southeast Asia (at or before 49–46 ka), gypsum pigment (40–33 ka), bone tools (40–38 ka), hafted tools (38–35 ka), and backed artefacts (30–24 ka), each up to 10 kyr older than any other known occurrence.^[36]

In the south-east the Murray Valley supported semi-permanent villages in bountiful areas like Kow Swamp c. 16,000 BP. Tasmanian archaeology has dated remains in Kutikina Cave to about 22,000 BP but subsequent digs in the south-west have extended this date back to about 35,000 BP, the oldest Tasmanian archaeological records.

In attempting to understand patterns of land occupation archaeologists have devised three important landscape categories: uplands, sandy ridges and corridors,^[10] the montane uplands, river and gorge systems providing the resources necessary for life. There were certainly widely separated communities more than 40,000 years ago but it is not possible to say whether this settlement was contemporaneous or sequential.

Studies of mitochondrial DNA from 111 hair samples performed in 2017 indicate a single rapid migration along the east and west coasts to reach souther, Australia 49,000-45,000 years ago and Tasmania by about 40,000 BP. There is a continuous presence of populations in discrete geographic regions during this period.^[37]

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.

SE Asia

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.^[43]

Austronesia

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.^[18] 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.^[25] 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.^[33]

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.^[35]

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 8^th to 9^th 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.^[45]

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.^[28]

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.^[31]

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).^[29]

Timeline

BP

2 million – Emergence of genus Homo in Africa
2 m -50,000 – Homo erectus widespread across Eurasia
c. 300,000 – Fossils of Homo sapiens found in Morocco suggesting Africawide distribution at this time
200-150,000 – Homo sapiens found in fossils of East Africa
80-90,000 – Anatomically modern humans leave Africa to populate the world
70,000 – earliest evidence of modern humans in SE Asia
65,000 ± 5000 – earliest evidence of humans in Australia
50,000-10,000 – Ice Ages, peaking c.18,000 BP, with sea levels 100-150 m lower than today
50,000 – H. sapiens populates Australia, preceded only by bat & rodent placental mammals
52,000-40,000 – World’s first figurative rock art found in Borneo and Sulawesi
43,000 – H. sapiens populates northern Europe
43,000-22,000 – Lake Mungo a fertile lake system –site of oldest Aboriginal remains
35,000 – H. sapiens populates Tasmania
30,000-25,000 – General occupation of Sahul complete(except arid centre)
30,000-5,000 – Volcanic activity Mt Napier, Mt Gambier, Mt Eccles
25,000 – H. sapiens populates Britain
18,000 – H. sapiens populates North America
14,000 – King Island separates from Cape Otway
13,000 – Flinders Island separates from Wilson’s Promontory
12,000 – H. sapiens populates South America
. . . Gwion Gwion Kimberley rock art dated to about this time
10,000 – H. sapiens the only remaining species of Homo
8,000-6,000 – Formation of Great Barrier Reef; separation of New Guinea & Australia by Torres Strait
6,000 – Sea adjusts to present-day levels
5,000-2,500 – Peopling of the Pacific
4,500 – Chinese farmers migrate into SE Asia
3,000 – Settlement of Torres Strait Islands
1,500 – Trade route connecting Mediterranean, W Asia, Africa and China with minor trade into Indonesia
1,000 – Settlement of Polynesia

CE

300 – Settlement of Easter Island
400 – Settlement of Hawaii
1280 – Settlement of New Zealand
1980s – Genetic anthropology begins mapping the path of human migration
1987 – mtDNA traces human family tree back about 10,000 generations to first female ancestor ‘Eve’
2011 – First completed Aboriginal genome

Key points

• The genus Homo evolved about 2 million years ago
• By c. 300,000 BP modern humans, Homo sapiens, were widespread across Africa
• Of the five species that existed 100,000 years ago only one, Homo sapiens, remained by 10,000 BP
• All anatomically modern humans are the progeny of one lineage of people migrating out of Africa c. 60,000-70,000 years ago
• By 55,000 BP Aboriginals had settled in Sahul (Australia) which was 10,000 years before H. sapiens arrived in northern Europe and 25,000 years before their first occupation of the British Isles although other species had arrived long before
• Genetic anthropolgy using genetic markers has determined major human lineages and their ages which, when combined with archaeology, has assisted determination of prehistoric paths of migration
• Aboriginals probably entered Sahul in the north-west through Flores and Timor but also possibly via Sulawesi
• Migration patterns within Australia are uncertain but probably uniform (saturated)
• The centre being occupied by at least 30-40,000 BCE when rainfall was higher and lakes were present
• Tasmanian archaeology dates back to about 35,000 BP

Plant commentary & sustainability analysis

Aboriginal occupation of Australia occurred about 25,000 years before the occupation of Britain by modern humans after the last Ice Age. Aboriginal ancestors walked across the world, a journey that took 10,000 – 20,000 years and averaging around 1-4 km a year. Assuming this pace was continued, the Australian continent would have traversed in 1,000-4,000 years.

It would be over 50,000 years before Europeans would make the same journey to Australias, but this time in ships.

The effect of transport systems becomes clear when we compare approximate travel times from Europe to Australia through history: 65,000 BP, walking, 10,000-15,000 years; 1650-1800, sailing ship, 18 months; 1850-1870, clipper, 2-3 months; 1900-1920, steamship through Suez Canal, 35-40 days; 2000, aircraft, 1 day.

The environmental impacts of Aboriginals within Australia will be discussed in subsequent articles.

*—

First published on the internet – 1 March 2019

. . . revised 25 September 2020
. . . minor edit 3 September 2021
. . . 4 July 2023 – minor edit

Map outlining migratory paths of Austronesian speaking populations, including estimated dates.
Adapted from Benton et al., 2012. M. Benton M; D. Macartney-Coxson; D. Eccles; L. Griffiths; G. Chambers; R. Lea (13 April 2012). “Complete Mitochondrial Genome Sequencing Reveals Novel Haplotypes in a Polynesian Population”.PLoS ONE 7 (4): e35026.DOI:10.1371/journal.pone.0035026.
Courtesy Wikimedia Commons – Obsidian Soul – Accessed 14 October 2020

Early human migrations. Courtesy Wikimedia Commons – Dbachmann 2018 – Accessed 27 July 2023
Features shown:

200 kya East Africa [“200” symbolic of early H. sapiens (est. age of mt-haplogroup L ranges around 180 kya, early divergence in Africa as early as 300 kya but cut-off for “anatomically modern” vs. “archaic” is somewhat arbitrary in this case)
130-100 kya expansion within Africa and to the Levant
70 kya “recent Out of Africa” and coastal migrations
65 kya peopling of Oceania
60 kya “Indian” and “Indochina” (Laos) population centers
50 kya “Near Eastern” population center (Emiran)
40 kya “East Asian” population center
40 kya peopling of Europe (Aurignacian 42 kya)
40 kya approximate peopling of Tasmania (add more detail on dispersal in Australia and to Papua?)
35 kya peopling of the Mammoth steppe (Mal’ta–Buret’ culture 24kya)
35 kya Expansion from East Asian population center (Korea 35 kya, Japan possibly 35 kya / certainly by 14 kya, Taiwan between 30 and 20 kya, Cambodia by 20kya [Sơn Vi culture] — but possibly earlier “Austronesian” presence 70kya?)
25 kya Beringia during the LGM
16-14 kya peopling of the Americas just after the LGM (Clovis)
12 peopling of northern Eurasia after the LGM
12 peopling of the Green Sahara [Mali]4 Paleo-Eskimo expansion to the Arctic (AST = Arctic small tool tradition)
3-1 Austronesian expansion
1 Norse expansion to Iceland

Dbachmann 2018